Ask at local quilt shop for basic classes and also if there are any quilting guilds in your area. You might even try a search on line for quilting guilds in your town. A lot of churches have them too. Keep practicing
keep practicing and slow your sewing speed down alot. Just because the machine can go fast doesn't mean it has to.
Can you post some pictures of your work. I would think it is not as bad as you imagine. We are all our own worst critics.
Another idea is to make something like a table topper or small wallhanging rather than a big quilt. Big quilts are very bulky and hard to manage sometimes. They can pull your work out of the 1/4" seam if they are not supported well when sewing all the rows together.
Don't give up, I didn't!
peace