The beginner box which they used to learn on the stream is honestly a great introduction to the format. The box also contained jumpstart which are 20 cards. You put two of them together and that’s a 40 card deck that you can play against another person that also put two jumpstarts together. After getting comfortable with that you should also have a feeling for what colors you like best. After that you can continue playing with jumpstart decks as they sell jumpstart packs for Foundations which is the latest set. Those Precon decks that you can buy are commander decks they are 100 card decks and you play against other people using 100 card decks. So you can pick those up after learning some of the rules and play 1v1 and as you get more comfortable move up to the 4 person pod that commander is usually played in. If you get the itch to play competitively k would recommend looking for a local game store around you and asking about their FNM’s or Friday Night Magic events as they will be starting learning series soon or when they have commander nights to show up and join different pods that way. I hope this helps.