Well, both in fact.
Playing Cavalry requires a constant amount of money, so in a bad day, you can take that gold loss, but you won't get bankrupt from it.
Just.. get to a stable state with your cash/upkeep, and then slowly add up items, see what you can handle.
Playing Cavalry also requires attention, and you can go down fast, so the fun/upkeep ratio can be mean if you ask me.
Also yeah, keep up levelin', and learning the game mechanics.
(tip: Don't play around with horses in the early levels, you'll just end up dying even faster.)
Hope this helped.