What sorta Mountain Bike should i get?

hey i recently thought i should start getting fit for summer and i live on the south coast of spain and have ridden along it before and loved it last night i was thinking i should get a new bike and start getting fit as i love riding off road i used to do motocross so i thought i should give mountain bikeing ago but dno what bike to get i wanna spend around 200 to 300 euros on one i want somin that's light comfy can handle jumping preferably with disc brakes any suggestions on what i should get ???