At two days old you're not going to be able to be doing much wrong. Just don't overwater, keep the temps in control, and you should be good! I say in about a week you should transplant out the solo cups and into bigger pots. 3gal is a pretty decent size, could also even be their final pot if you decide it to be.
Like Brimck said, just leave 'em be. You have more of a chance fucking up your seedlings by fucking with them to begin with.