Hobby boxes and packs usually have better odds but higher cost. As the other poster said, it is down to Topps/Bowman with a MLB license (team logos), and Panini/Donruss with the MLBPA license (just the players with airbrushed out logos). Prizm is a special release from Panini. Fat packs are the packs you see at retail stores (Target and Walmart) that usually consist of like 30+ cards. You can also have boxes that will get you around 70 cards, and jumbo boxes (but I can never find them) with even more, I think around 120 or so.
Cards are severely inflated right now because so many people with extra time on their hands are getting back into it, and celebs and even players are talking about cards that they collect. If you want a really good way to get back into it, I have found that a majority of the Twitter people that I interact with are really inviting. There are a ton that do stack sales of individual cards, you pick what you want, they give you the total including shipping. Also you have "breakers" that buy boxes and cases, sell spots for teams or random spots in their breaks and then ship out all carss that are opened from that box that match the team you pick or receive.
There is a ton of info and no one stop "cards for dummies" space to pick it all up. But good luck as I just recently got back into it too and spent about $300 of the "stimulus" that I got lol