Way to level up faster?

My characters are all so low level, and without gold or equipment to level up, it takes VERY LONG. Is there a way to go about this better?

Without gold and equipment it will be hard. You’ll have to grind dungeons a LOT. This is a game of grinding, so I guess there is no other way, unless you want to open your wallet.
There are a few walls players run into, lvl 4 is the first one.
But you know, that just makes it the type of game it is. It is a bit like forager. A grinding game with an ending (clearing explore or the final dungeon) and when you’ve reached it, you can go for completionist (get all characters to 20, max out every item) or uninstall.