Hello Agalardi,
Defnitely you should get to the Angel Falls to visit the highest waterfall in the world, located in th emiddle o the jungle in the Venezuelan state of Bolivar. You may also want to head out to Merida where you should be able to find accomodation for US $ 10 a night per person. Merida is located in the Vzlan Andes, it is a student town which offers many activities for locals and foreigners alike. As for beaches you may want to check out the Costal town of Choroni/Puerto Colombia in the Henri Pittier National Park, a great place to enjoy the cloudforest and some amazing beaches. As for diving you might want to consider Los Roques, an archipelago approximately a 45 min offshore from Caracas. Great beaches, some of the best the Caribbean has to offer, amzing snorkeling and scuba diving.
Hope you find this info useful. If you need more info/ help just let me know.
Travel safe!
All the best,
Thomas
Caracas
berry_venezuela@hotmail.com