Now that they have sprouted you can lose the humidity dome and drop the light down closer...like within a few inches from the top of your plants, or they will stretch like crazy. They can stay in the solo cups for a few weeks.
That site will help you get started in the right direction. I usually also recommend picking up Ed Rosenthal’s Marijuana Growers Handbook. It’s a huge book that I found so much easier to understand than a lot of stuff I found online.