I'm looking for wider varieties of stuff that can be done without access to a gym/special equipments, as all I have are various weights of dumbbells and a barbell.

You are well-equipped! Seriously, other things can be fun to have, but you've got the basics to do a HUGE range of exercises.

Stumptuous has a bunch of exercises and entire workouts you can do with those, including a dumbell-only workout.