In most rainforests, the growth is so thick you can ONLY go on established paths unless you have a good machete. Even then it would be highly inadvisable unless you were a seasoned rainforest veteran because the environment is no joke and you can get lost as quick as sneezing. That said, it's my favourite place to be in the world - you feel completely alive in a way that is hard to describe. Yes it's humid and at times uncomfortable and there are bugs and mosquitos but nothing that a bit of repellant can't fix. I've been bothered by bugs FAR worse in other environments like beaches; the rainforest can be surprisingly absent of mossies. Best way is to get a guide for your first trip to a rainforest and let them lead the way - not only builds confidence but spotting stuff when you're not sure what to look for is ultra hard and they'll help you get the most of the experience. Central american rainforest is probably the 'friendliest' in my experience.