Legal Structure's and DBA's

I swear this is going to make my head explode. I don't understand why it has to be worded in such an ambiguous way. I'll be going with a sole proprietorship mainly because my 'business' is just me selling art. I don't want to sign up for one right now, though, mostly because I really don't have the money at this moment, but also because I'm not even sure how well this is going to pick up. I would love to spend all my time on it, but I have school.

• I think I'm going to go with a dba. Still not 100% sure what this means but I think it's best for sole proprietors.
• Again, don't get what this means, but I can run my business under a name that is not mine, for instance pineapple- however, I don't own that name, I just get to call myself that.
• I'm hoping it's cheaper and less confusing than an LLC.

If I ever get enough money, I'm going to pay for someone else to do this for me.