Hello! I recently acquired a rescue turtle who has been living in a daycare for all two years of his life. His previous enclosure (first picture) was obviously inadequate and when he was surrendered to me he was given to me in a bin. I set up his enclosure with what I had on hand and bought some extra supplies to make it adequate. He currently has a heater in the water, two UVB bulbs one for the basking and one for the water, a basking bulb, a white led for the water, a small filter, and general decor I had on hand. He's currently in a 40 breeder. (All seen in the second image) All of this is just context for my question. 

I was wondering if the following behavior is normal? He's been swimming around in his new enclosure A LOT. He's going around pretty fast back and forth and greeting us when we approach. The first day he had the basking bulb he sat under it for several hours before finally going back to the water. Now today I haven't seen him bask and he's just going kinda wild. Is this normal??? I'm worried it's stress behavior, but I'm not entirely sure. I can read all about husbandry all day, but when it comes to turtle personalities I'm a bit lost at the moment. 

Any answers and advice is appreciated! Even if you don't really know if he's stressed and you just have a comment about his tank I'm more than happy to listen. First time turtle owner with a surprise turtle I didn't expect to take in! Thank you!

Got a rescue and I'm concerned about his(?) behavior?