Wow, it goes both ways. Today I got fabric for a future quilt that needed a 6th print for. I am also collecting fabrics for 3 other quilts and don't have any idea what pattern I am using.
There are pros and cons to buying the fabric before knowing the pattern... mainly, will I buy enough? There are deals out there that are just too good to pass up and that's when I buy a few yards of each.
If you pick a pattern, you will have a better idea of what you should be shopping for. I made my daughter a queen size in teal, taupe and cream and she loved it (teal is her favorite color). The pattern was simple and I couldn't wait to wrap it for Christmas. My other daughter wants a simple Italian flag. Working on that too.
The patterns for beginners are something like a four patch square. That goes fast and it's simple. Also a strip quilts pattern. Good luck.