Advice on 2 year old - please read

I feel like I’m failing. My son is two. He will be three on February 4. I need advice on his behavior. He’s constantly hitting and I mean CONSTANTLY. He’s very aggressive sometimes. No matter how much times I say no or stop or correct him he will not listen. He does have a slight speech delay. Nothing the doctors are concerned about yet. He doesn’t combine two words. But he understands everything, says about 100+ words.he’s very smart. He’s extremely active. And he can be so so loving. But his hitting is out of control. And he just acts crazy sometimes. He is on the move all day long. And jumps all over the furniture. I sometimes dread taking him to friends/family houses, out to stores etc. he’s extremely picky with food too. He’s very playful though loves kids. I’m just wondering is this normal behavior or anything I should be concerned about? And please say more than if I’m concerned to mention it to his doctor .I am going to bring it up to his doctor he has an appointment next week regular check up. I’m just curious to see what other moms think