Newer threads leave less "fluff" in your machine. I use Glide for nearly everything. It is polyester, smooth, strong and comes in a wonderful array of colors. I do use it even when sewing on cotton fabric. The reasoning for using cotton thread on cotton fabrics was that if there was stress on the fabric, the threads would give and the fabric wouldn't tear. I have never found that to be a problem. Maybe you could do some experiments and let us know what you think.
The best basic quilting book I know of is an old one by Laura Nounes, (Nownes ?), "Quilt, Quilt, Quilt." Maybe someone will write in with more accurate spelling or a more current book, but I did learn a lot from that one. Once the Covid crisis is over, taking classes is a great way to learn, too. And so is YouTube.
And welcome from sunny Southern California!