Toddler does not listen at all

My son is 3.5, he’s my first so I’m learning as I go. But everyday is such a battle, I have to ask him 10-15 times to stop doing something he just doesn’t care. I tell him he’ll go in timeout, take toys away, etc he doesn’t care & does not listen. So he goes in timeout, comes out and does it all over again. This is an all day everyday battle. It’s is so exhausting. I try to teach him how to do things. Like the animals, he is SO AGGRESSIVE to them. I show him how to treat them, explain, over and over and over he doesn’t listen. He wants to help cook, I show him how, give him tasks, but he’s trying to grab knives out my hand, etc. it makes everything impossible bc he is not receptive to anything I try to teach or explain. I ask him to get out the bath for 20 minutes, he’s fighting me, jumping around, I have to physically drag him out and he’s jumping back in. I’m 6 months pregnant and don’t have the strength or ability to literally wrestle him daily. I feel so bad as I have to literally scream at him to get him to stop. I try so hard to sit and talk with him, teach him, ask him why he’s doing XYZ, I try to talk through everything but he’ll just yell over me and say “STOP TALKINGGG”, and cover his ears. I’ve tried a gentle approach, punishments approach, everything lol. I don’t know if this is normal toddler behavior or if something else is going on behavior wise. He’s such a smart and sweet little boy. But for some reason he just does not take authority at all. Is this normal!? What can I do? I see other moms & they don’t seem to have such a struggle. I feel discouraged with his behavior & really want to correct this. I do want to add I do coparent, and he’s at his father for 3 days a week. The other children there I’m aware have had behavioral problems and I don’t want to point figures but I just wonder if the back and forth so much and seeing other behaviors is what’s causing this. But again, I really don’t know. He wasn’t like this before. This is new within the year.