Unsure if my puppy is bored

My puppy is currently 14 weeks and I have no idea if I’m not doing enough to keep him entertained. I usually take him out for 4-5 20-30min walks a day. I feed him using puzzles or train him during our walks. Whenever we aren’t out I usually train him or he likes chewing on his toys. He usually doesn’t like playing with me, he rather play by himself. I have a ball that I put treats and he plays with it for quite a while. He isn’t a bad puppy. He doesn’t chew on things he’s not supposed to. He usually takes about 3-4 naps a day. He recently started biting his bed and humping it before he settles down to lay. I read that it may be a sign of boredom so I am unsure if I’m doing enough. I feel guilty when he’s just laying. If I’m not doing enough please let me know what I can do during our day. He’s a hunting breed.