That's because he's hired for a made up position by his billionaire adopted father.

Tobys spiderman had it right, he rented a space that fit 1 bed and a desk. He shared a bathroom on the floor too. He could barely afford that.

Maybe he's squatting at the apartment of a blind lawyer who disappears for months at a time.

Don't ask why the landlord hasn't been seen for months

he door dashes A LOT

nobody can beat his delivery times

So they could’ve called it Brand New Home.

How much would a place like that rent for?

I mean, he got a pretty good settlement from when aunt May died. Also, he was the protege of Tony Stark so...

Maybe he earned a lot more money than we thought in that brief period at the start where he tried to use his powers in the underground fighting circuit.

Stark probably left him hella money in his will. Or maybe Shield or the Avengers themselves hooked him up.