The boilerplate answer for this kind of question:
Take 2 gathering professions (ie mining and skinning) while you level up. You can sell whatever you get and help pay for expensive things like riding training.
Blacksmithing wont help you as much as you might think from 1-70(ish). It can be tedious and expensive to level, and many of the items are kindof mediocre.
Once youve started to get close to 80 you can evaluate the other crafts to see what you might want to do based on BoP or crafter-only recipes. Some examples of these...
Blacksmithing: You can socket some of your own items and there are a few nice BoP items.
Inscription: Shoulder enchants and some BoP off-hand frills that primarily benefit casters.
Jewelcrafting: Trinkets and BoP gem cuts that are a bit better than the standard BoE cuts.
Enchanting: Ring enchants
Engineering: The ever-popular goggles.
(yadda yadda).
You may even opt to stay with the 2 gathering professions, as they give you buffs (skinning gives crit rating, mining gives health) or abilities (herbalism gives you a self-HOT).