Yes definitely take advantage of single rider lines!!
Also, one of the most fun parts about going solo is just being able to do whatever you want and follow your own whims! Always wanted to try a certain restaurant or bar but could never get the fam interested? Boom. Do it. Have an absolute favorite ride that you could do over and over and over again? Do it! Seriously, while I much prefer going with my DH, being solo at Disney parks is its own kind of fun
One thing I had to be hyper aware of as a solo traveler (and for me personally, a solo female) was walking to my off-site hotel at night. I would stay 'til close and I was at a hotel a couple blocks away and I walked. I never felt unsafe, but I always made sure to be near a group of people and at one point even asked a few other girls if I could walk with them since I was by myself. Of course, if you're staying onsite then this isn't as big of an issue!
Most of all, enjoy your solo time- it's such a special way to experience the parks