first mash

I'm looking to do my first all grain batch but I don't have a big enough pot or a stand alone burner. Is it possible for me to do a half mash, boil it, then store it in a fermenter while I mash and boil the second half of the batch

Sure...no problem. Don't let your 1st batch sit too long though. Couple hours ok but not overnight.

Yeah I was planning mashing the 2nd round while boiling the 1st

Sure you can do this, you can also mash a high gravity wort and dilute w/ water to proper gavity, but your efficiency will suffer a bit, as will hop utilization. Another option is called the Texas two step, make a 1/2 batch and pitch the yeast, the following day make another half batch and add it to the first 1/2 batch...

Or if you have a second pot, you can split the boil in two pots.

Or if your mash tun is big enough, you could do a full volume mash, drain off half and boil, then drain off the second half and boil...many ways to accomplish your goal.