Welcome...And congratulations on a great quilt !! ...your piecing and quilting certainly do not say "first time" to me.
Lots of good suggestions here... I agree with Feline fanatic that a sampler is a nice way to learn different blocks and techniques...
The other suggestion i would make regarding fabric is what i used to do when i was starting out - and still do sometimes today.... I would pick a multicolored floral that i liked....then use it to pull other "solid" colors (fabrics that read solid but had subtle pattern in them) from the colors that were in the floral. The selvage edge will have dots or squares of the actual colors in the fabric. That way, i knew that the colors would go together.
Good luck....can't wait to see your next finished project !!