All those bikes are basic economy bikes, cruiser types most likely. From a vintage standpoint, not of much value. They are to you though ! I 've no better ideas as far as starting out, cuttin' yer teeth in learning the craft of fixing. Ross was a Co. based first in NYC then Penn. They went away by the '90s. It's no Schwinn but I liked them, they were lighter than some bikes and OK. Google using Google as a brouser, NOT yahoo or Bing or...That is to read abvout them; not as important. It's even LESS important for the likes o' me to go on about them. The other bike's a Murray, not bad either for what it was and what it is now.. FREE.

I recommend that you get a copy of Cuthbertson's Book, "AnyBody's bike book". Park has a book too but it's beyond what you need. Though it too is cheap to buy, Cuthbertson's book focuses on the old stuff more, is easy to follow and fun.
A book in hard copy (or soft) is handier than a key board.
The bikes are probably 26", an odd type 26". DON'T buy tires yet, not yet, they should be the LAST thing you buy. They can be had later at the very end. I also recommend that you buy a can or two of PB BLASTER; better than Liquid Wrench & others, though use what you've got for now. PB' available at Parts Stores.
The bikes use generic parts; simple and cheap. LBS (local bike shops) can be a good source. I've visited stores up where I used to live that laughed me outa the joint the odd time I needed something. NOT SO where I live now, near the beach, Lots o' beach cruisers. You simply need to find a cooperative shop. ON-Line's OK too but for now, to start, find a shop who's... well.. you know what I meen.

You want to fix the old bikes. ZERO risk; if something breaks, no biggy, the very best way to learn. In the end, you'll aquire knowlege and a couple/ few fun bikes.