My 3 month old puppy is very temperamental and he keeps biting and misbehaving?

My puppy is a Yorkie and Maltese mix and he is very tempremental . I've never had a dog before so i don't know how to to control a dog . He was in puppy cles but we didn't really learn much , I don't know what to do . He keeps biting everyone including me and he always barks at people and scratches . I want to have a well behaved puppy but hes just being so bad . And when i try to do the things that the trainer taught me , my family undermines me and doesnt follow the rules of puppy training . How can I take a gentle route to train my puppy and have him trust and respect me . I feel like hes out of control and i just got him 2 months ago .