I am a relatively new quilter, too (and I'm a few years older than you). I've made two quilts so far and am contempating my third one. My first two were more twin size, but we are expanding our long arm to 10 ft, so the next one will be a queen size. I am anxious to use the new, longer table, so I will do a simpler design this time - something like a rail fence.
The first photo below is a design I'm leaning toward. It's only 3 colors and if you use Jelly Rolls, each block ends up at 6" finished. (I will probably use wider strips to make my blocks bigger.) I like the idea that each block is the same.
The second photo is my second quilt. It is also a "rail fence" type (just strips sewn together to make blocks). It actually went together pretty quickly as well.
These are just some ideas. I think you are smart to keep your first quilt sort of simple. It's nice to see quick progress early.