First thing you should understand about trade in Mount & Blade in general is that certain conditions in each playthrough effect the prices and production of trade goods, sometimes significantly. That being said, there are a couple ways that i found to be consistently profitable and this (sorta) guide will be about those.
If you've looked at some other trade guides for previous versions of Perisno you'll see that the northern half of the map rarely gets mentioned. The main reason for that is the lack of precious good production in the northern (Maccavia, Reich, Valahir, Sut and Tolrania) regions. There is also the fact that the northern half of the map has the tendency to turn into a bigger shitshow compared to the southern regions right from the start of a playthough; with constant wars, changing borders and looting of villages. Again, this is not something that's set in stone and as trade goes in Mount & Blade, you should look around and see for yourself what is profitable and worth the time.
In regards to character creation, i'll leave that part up to you as you can see the stats the character creation options give you and you can play around in it to also get some secondary stats to make it easy to transition into a combat capable character; i'll just suggest that you should aim for decent (>5) trade, inventory management and path-finding. I'd also like to note here that if you'd like, you can just ignore getting any points in trade and instead hire Fazl as he's a relatively cheap companion with 8 trade though you'll have find him in a tavern first. Some other companions also have decent path-finding, but inventory management is not a party skill and you should aim for at least around 5 in the early game as to not get into constant inventory issues. If you're planning to use trade as a base to grow your wealth in the early game and then transition into a combat oriented play style, i suggest you use your own skill points on skills like leadership or persuasion instead of trade or path-finding and utilize your companions to make up for your low party stats. You should also note that simply going around and trading will NOT give you any experience points so you'll want to eventually get yourself a small party to level up through quests and bandits.
Now, let's get to the point. There are 3 trade goods that stay relatively consistent through each playthrough as worth trading. Those are raw silk, salt and iron.
- Raw silk is the most profitable trade good in the game that i've seen. It's also the least time consuming and easiest to trade. What you want to do is buy all the raw silk you can find in Elsinore and the surrounding villages of Oyens, Themar, Esari and Istle. The village of Slenor is also right next to Elsinore, though i don't think i ever found raw silk in that village, still it's worth checking out when you're near there. After going around getting all the raw silk you can get, all you have to do is go to Lille to offload your silk. In certain times you'll be selling the silk for 10x more than what you paid, especially if you can find them cheap in the villages. In my experience Lille is the highest paying city in the game for raw silk despite it's close distance to Elsinore, so this is definitely worth doing every once in a while. Weird enough, Reichberg all they way up in the north also stocks some raw silk for good prices, so keep that in mind if you ever get around there. The reason for your inability to constantly use the Elsinore-Lille trade route is that you need some time to pass for cities' and villages' inventories to refresh and stock up on more silk. That's where the salt comes in.
- You have two primary options for getting a large amount of salt cheaply, those are Arish and Khul Vara. Both stock a good amount of salt though it may vary. I also regularly check the villages around these cities though they also seem to vary with how much salt they have and how much they charge for it so they are not as consistent as the silk villages around Elsinore. Other cities in Hakkon and Drahara may also stock salt in decent amounts but i suggest you check their prices first as they might not always be cheap enough to worth buying. You can possibly go north to offload the salt for a good price, but i found that Krain pays quiet good for salt so you can simply sell there. As with every tip in this guide you should check the prices before mindlessly buying/selling, always keep in mind that things can change across different playthoughs or even in the same playthrough. Additionally, you can check Khul Vara when you're there for spice as the city might have them in decent amounts for cheap though it's not as consistent as salt or raw silk.
- Admittedly iron is not as profitable as salt and silk but it's good enough to be mentioned in this list. You'll want to go into the Kaikoth Confederation for this and again it's worth checking the villages for iron. I think every single Kaikoth village stocks some iron and i could find it for cheap in most so it's worth checking out all of them. The city of Karnoth will be your main source for cheap iron aside from the villages. The other Kaikoth city, Dwallnor, also stocks a good amount of iron but it's usually much more expensive than in Karnoth and thus not as profitable. I also suggest caution if you encounter any gold ingots or gold ore in Kaikoth Confederation, i know it sounds like a good idea but i rarely profited from gold purchased in Kaikoth. You can offload the iron you got for good prices in basically everywhere else, if you can sell it for 2x-3x more than what you paid for it's generally a good idea to do so as iron slows your movement speed in the campaign map considerably.
Of course, these are not the only ways of profiting from trade but they are seemingly the most consistently profitable while also being the least time-consuming. There are a couple other fine sources of goods like Lesbere for ale or Valahir cities for flax; but they are definitely not as good as the ones mentioned in this list. As you spend more time in a playthrough and explore, you'll certainly figure out more trade routes as you familiarize yourself with the prices of various goods in the game so be on the lookout and check the cities and villages on your path to expand your options and use the free time between the inventory refreshes that enable you to use the trade routes mentioned in this list.