Hey Shontaka,
Please take a few minutes to read the
Trade Skills Sticky.
Traditionally, Engineering is paired with Mining as you'll need the metal bars for your Engineering recipes. Likewise, Leatherworking pairs with Skinning as the leather and hides you get from Skinning is used in your leatherworking. Tailoring doesn't really have a pairing as the cloth you need drops off humanoid mobs you kill. Jewelcrafting will likely be well paired with Mining since I think you'll need raw ore to "Prospect" for gems and the like.