Bought new polaroids & I dont know how to tell if they work!

Hi!

My boyfriend and I bought three Polaroid cameras from vintage antique store today, two of them are Polaroid One-Step 600's (one looks like an older model than the other and one is totally different looking the top more pops up just a tad totally different shape and this one says "Spectra System". You can clearly tell I know nothing about them I just need someone to tell me how to see if they actually work and where the batteries even go? Totally mind blown ! haha