Many of us are lone quilters and have had to improvise patterns to our needs. It's not that hard and gets easier to do as you get a few quilts under your belt. This is a wonderful site to learn on. We are many of various skill levels and tastes. When in doubt just ask and you will get answers. If you post photos of your stuff, it's easier for someone to get what you are trying to solve.
Smaller quilts go faster and you get that pat on the back sooner but if you want something larger, most things can be enlarged by either making more blocks of adding borders to it. If you get a kit, you have to remember the fabric in the kit is for the size it states and you will have to purchased more fabric if you want it larger and at shops, that fabric isn't generally available and you will have to alter the look of the quilt. It's sometimes easier to stay with the pattern till you get confident and then venture out but only you know you and what you are comfortable doing. Welcome, I look forward to seeing your quilt.