Hi Boo - welcome to you and your new mum and dad to champdogs.
Oh boy, I can still remember our Dylan when he was your age (he's now 8 months and weighing in at 56 lbs !

) He has a big brother called Rufus (he's a 4 yr old springer cross) and they both play really well together. I wouldn't be without either of them :)
Boxers really are gorgeous dogs, quick to learn, easy to train - we have a little windchime on the back door and we taught him to ring it when he needs to go out, by the time he was about 14 weeks he was ringing it on his own asking to go to the toilet - of course now he rings it with gusto when he wants out, the kitchen door open, the kids downstairs, me on the sofa gving him cuddles, when he wants to play...... :D Currently he's asleep with 'Uncle' Rufus on the floor next to me waiting for me to say 'bedtime' so that he can beat me upstairs and get on the bed before me :rolleyes:
Good luck with him, we're all here for you if ever you have a problem with your new mum and dad - like they haven't got you enough treats :D