New dog owner worries

I’m a new dog owner, as in, he came home yesterday. He was already cratetrained and housebroken. He’s a mixed breed 4year old.

My thing is, he needs to be pet Constantly. And it’s not enough to sit at my feet, or even to have my hand on him; he loves pets and being picked up.

My first question is: can I train him not to need to be picked up and pet all the time without stressing him out? I want to hold him and pet him, just not all the time. When I ignore him, he’ll back up into me or lay or me or shove his nose in my hand.

But when I don’t give him attention, I find he just goes to his crate and lays down, no whining or crying. The door stays open, so he must like his crate, right? Or at least it isn’t threatening to him.

But now I feel bad, like he’s slinking off sadly when I can’t give him attention. I don’t want him to feel dejected. Realistically, this is all in my head because he shows no signs of being scared, sad, mad, anything. But this is my first dog and I want to make sure he’s comfortable and stimulated.