how to properly confront a man (45m) at my (30f) gym?

there’s a man whose much older than me, divorced with 2 kids from a woman who is of the same cultural background as me. idk why he felt the need to mention this.

anyways, first time we spoke it was because he asked me to hold his back while he did a workout and i said NO. then we chatted briefly, he asked for my instagram and i stupidly gave it to him because i figured it was just another gym buddy to add. i didn’t end up accepting his request because i just felt like something was off at the end of our conversation.

but now he makes me super uncomfortable, he will occasionally come over to me and ask to share a machine im using (i agree cause again im trying to treat everyone equally) but he puts his hand on my back to tell me it’s my turn sometimes and i hate it so much.

today, as i was walking down stairs he said “there’s my beauty queen”, i ignored him and pretended i didn’t hear it. later there was no way to avoid him later so i just gave him a pound and i quickly walked away.

i really hate him, i feel like he knows im uncomfortable and does it anyways and im not strong enough to speak out / scared of him.

what is the best course of action here