The long road to back in shape....questions along the way...

So after having been out of the water for about a year, I'm finally starting to get sort of a routine of going again. I know it was going to be rough, but the last few practices I've felt actually really good in the water and been able to hold times fairly close to where I was before I stopped. It hasn't been that long (a few weeks) since I started again so is just my body reacting to something new and being good (like beginners luck) and in a few weeks it'll feel like concrete again? Or are my muscles actually remembering what they were once able to do? I'm not complaining I just want to know if I'm going to hit a wall soon. I've been going last in my lane, but I'm starting to ride the feet of people in front of me. Should I keep going last and taking it slow for a few more weeks, or is it better to push it and try to get back in shape faster? When should I add in dryland? I don't want to do too much to fast and hit a wall hard or hurt myself. Also, knees. Is it better to be a little paranoid or just suck it up? Before I stopped last year, my knees had started to get sore and pop a little when I would do breaststroke. Sure enough, it's starting to do it again. I've laid off the breaststroke for the most part now and am doing with a dolphin kick instead. Should I just start going to the gym and doing squats? When is a good time to see the doctor if at all? Thanks for all your help!!!!