>>715043196
>open Monkey Meadow on Easy
>pop bloons
You'll pick it up as you go along, you don't have anything besides Quincy and 000 Dart Monkey to start with.
New towers are unlocked with levels, except for four special ones you have to unlock with pops.
Tower upgrades are unlocked with exp, which you earn every round you have one of those towers on the map. More towers of one type = more exp for that tower.
Monkey Knowledge is earned with levels and unlocked Monkey Money. You get more MM from doing map medals you haven't beaten before. Your first three MK should go into the Magic tree, for Mo' Monkey Money, a permanent boost to basically all MM earnings.
You need levels and MM to unlock new Heroes. Sauda is generally regarded as the best hero for beginner maps and new players, since she excels on single lane maps. That or Benjamin for his money making. Geraldo and Corvus require a lot of micro to be really good and Churchill is way too expensive. The others are varying levels of good-to-crap.
Don't bother trying to start any Race, Boss or Odyssey events until you've got all base towers and all their upgrades unlocked, it just won't work.