If it's a rainforest, water purification probably wouldn't really be that necessary. It rains a lot in rainforests weirdly enough. So if you could hollow out the inside of a fruit or something you could probably just collect pure rainwater and drink that. Might even flavour it a bit. If purification does become needed, then there's a few ways to do that too - sand purification, boiling and all that.
There'd be plenty of food options too. Fish, fruits (if you can recognise the safe ones) and lots of other wildlife you could potentially hunt and cook. Everyone knows in theory how to start a fire so with enough trial and error - and a dry enough location - that couldn't be too hard to deal with either.
The real trouble wouldn't be finding food or water it'd be not getting eaten by an apex predator, poisoned by some sort of snake or spider or given a blood borne disease by a swarm of mosquitoes. Oh, or dying of exposure. One of those things would definitely happen to me lmao and if not, I'm way too sick to actually hunt food down. So yeah, I'd be fucked.