New here.... tires question

[Primer69er]

Whats up everyone, I just bought my 1969 chevy c-10 friday night for $250 it has a 250ci inline 6, granny 4 speed, lotsa rust and lotsa dents. on the way home i kept hearing a loud rattling noise, i figured it was the rusty parts rattling around, turns out the front drivers wheel had 3 out of 6 lugs missing and the other 3 were on the last thread.

but anyway my question is this truck has some white 15" wheels on it but the tires are 205/60/15 so it looks like its ridin on spares. i want some good tires that will fit the size of the truck. what size should i go for.

also on my wheel stud issue, whats the best way of changing those out, i took the drum off and am wondering if i have to take the hub off, or can i bang them out with it still on the truck???

Thanks in advance for any help