I'm pretty sure Ten specifies in The Christmas Invasion, when he's explaining why his hand's just regrown (or is about to); if you have access to that, check.

Since you've said this is a first regeneration, bear in mind that they tend to get more severe as the cycle goes on. The Doctor's first regeneration was very low-key, and he was back on his feet almost instantly. Melody Pond's second regeneration didn't really affect her at all - well, it made her slightly psychotic, but in terms of confusion, no.

You might also want to note the first (known) regeneration of Romana: she was apparently able to select her new form with a fine degree of control. This ties in quite nicely with the regrowth/repair aspects seen with Ten and River, actually.

Also: regeneration energy can be used as a weapon in that early timeframe. Again, see River's attack on Berlin.

And the main effect you've missed from the Doctor's regenerations is 'manic energy'. Four jumped up and started jogging on the spot; Eight got waaaaay hyper; Ten, Eleven, and Twelve all manically crashed the TARDIS. And, again, see River, though she was most of the way there already.

hS

... but ultimately decided against it for many reasons. Though during my research I found this. Is a little outdated but I think it might be useful for you

Leftover regeneration energy seems to stick around for at least several hours after regenerating.

So, what's this one's backstory? Rescued from a badfic? Crash-landed into HQ? Fresh from the Time War? If it's the last one, Emiranlanoamar would like to have a word with him/her...