What is wrong with my bearded dragon?

I think he's just getting used to the tank. Give him some things to climb on, etc... One thing I noticed if the temps sound off. I'm sorry, I don't speak celsius though:) you want a basking spot under the lamp about 105° f, which should be about 40.5°c by my calculations. Here its a good site with lots of good info on beardies, there are petiole on there from the uk and the us as well as other places. http://www.beardeddragon.org/

Your bearded dragon is just trying to get used to its new surroundings, that is all. Give it about a week to adjust and he won't do that anymore. Don't handle him for about 2 days either or more, because then it will take the bearded dragon longer to adjust to its new environment.

It could be one of three things: 1) He can see his reflection as you've suggested. This isn't that likely, but it's possible. It doesn't mean he wants a friend though. In the wild bearded dragons are not that social, they may come together in areas where there are the best feeding and temperatures, but will often fight and dominate each other - especially the males. They aren't human so don't really feel "lonely" the way we do - at best, they feel the urge to dominate and/or mate. 2) Now this is the most likely one - he simply doesn't realise the glass is there. Reptile vision is not like ours. They often have trouble with "invisible barriers". When he walks up to the glass - he can not see it! It is like an invisible forcefield. This is why sometimes reptiles will leap off branches towards glass, or rub their nose raw on the glass trying to get out - they just don't know it is there, the brain cannot process the concept or the sight of "glass". They can see there is something on the other side so they will always assume they can reach it. 3) Your bearded dragon could be bored. Animals that are spending a lot of time rubbing the glass could need a bigger tank, but a 3ft tank for a 2 month old baby seems fine to me so far. He could just want to come out and be interested in what's happening and be looking outside. It's probably a combination of 2 and 3. I would not get another one, you risk potential breeding or fighting in the future. If your tank is glass, cover the back and sides so it feels enclosed and he doesn't feel like he's in an invisible box, and if he starts to get any damage to his nose from the glass you need to address the problem - but this is pretty rare in bearded dragons as long as the tank is a good size, which yours is right now.