Start with common games first. Xbox, PS2, GameCube, are a good generation to start with. Nearly every game is widely available (the common ones) and the systems are cheap (under $50). When you collect try to get everything CIB (complete in box) unless you really don't have the storage space or care about that stuff. Most common games for those systems are under $10 some go for about $1. Once you get the hang of it you can go for handhelds, older retro consoles, or even current generation consoles. Once you start collecting you can build lists, rank them from rarest and most expensive to cheapest etc. I usually didn't tackle the rare expensive ones until I had all the common cheaper ones off my list. I also tried to get hardware as nice as possible. Check local game stores first as sometimes they're cheaper than online stores. I usually go into my local game stores (or drive up to 100 miles sometimes) with all my consoles in lists on Google Keep sorted by price range and rarity and I go from there.