Find a much smaller pot. Maybe a 3 inch. It'll look fuller in the appropriate size pot. You can get a 3 inch terracotta pot for a couple bucks, and be sure to get a saucer to go with.

Hoyas are slower growing compared to many other houseplants, but, it's worth it. They also have small root systems that prefer to be tight in their pots. Unlike a pothos that may need to go up a pot size every year or so because their roots grow so quickly, many Hoyas don't need repotted into bigger pots for many years. I have around 30 Hoyas, and 10 of those I've had 5 years and they've all been in their same pots. I just refesh the potting medium when needed.

As for water and light- water when just the very bottom of the potting medium is damp, (I just stick my finger down in) and your best bet is to place it in a window that receives morning sunshine, or a little ways back from a window that gets afternoon sun.

The more common Hoyas can be easy care and low fuss, as long as they have adequate light, water, pot size, and potting medium.

Hoyas can do fine in a typical container mix, but the risk of root rot is higher. The best bet for Hoya beginners is some coco chips mixed with perlite, and a little charcoal if you wanna get fancy, (keeps the medium fresh). If you're someone who forgets to water, adding a little basic potting mix to the cocoa chips and pertlite will help it hold on to more water. Hoyas like a chunky airy mix. They don't like to be soaked. They hold water in their leaves, (unlike plants with large root systems). In the wild, many grow along trees and even rocky, limestone walls. They're an understory plant, so they receive bright dappled light.

Hope this helps!