I am a self-taught sewer, and yes, you can do it. You just need patience.
You seem to have already made your decision about a machine, so my bits of advice would be:
Really do follow the directions, at least at first. I tried to save time by not pinning in my facings or basting things into place, and I always ended up having to rip out those seams!
Some things that are worth investing in - good scissors, I have Ginghers, and they have a lifetime guarantee, they are wonderful. Don't let anyone else in the house touch your fabric cutting scissors!
Fabric - I am biased, because I happen to own a website where I sell fabric. But let me tell you - cheap fabric and cheap thread will ruin your sewing project.
Cheap cottons, like the $1/yd stuff at
Walmart - is made of lesser quality goods. It will ravel and shrink up like crazy, in addition to just feeling stiff and yucky. Some of my favorite fabric makers include Michael Miller, Alexander Henry, Marcus Brothers, Free Spirit, and Moda. All the Disney stuff is licensed to Spring Industries, which is also a quality brand. There are lots of fabric makers that will only sell to independent retailers, so look beyond Hobby Lobby/Hancock/Joann when shopping for fabric.
Thread - don't get 100% polyester thread. It will literally melt when you iron it. I would suggest cotton covered poly thread.
I do not have a serger, so I use Fray Check on my projects, it's a liquid seam sealant.
To pre-wash or not pre-wash is a big debate among sewers. Personally, I prefer not to pre-wash. The fabric feeds through my machine more smoothly when it is unwashed.