Welcome to KH, WoolyLamb!
Here's my recommendation: Start with something that interests you and that will KEEP you interested. So the question comes back to you, what would you like to make?
Something large, like a blanket? Something small, like a dishcloth or washcloth? Something in between large and small, like a scarf? Something in the round like a hat or a cowl?
After you've decided what you want to make, look for "beginner" or "easy" patterns for that project and dive in. And if you get stuck, there are lots of very helpful, extremely friendly people here to unstick you!!!
Then when you're done, come back here and show us a picture of your final project (please! because we love to see finished objects)!!