There are some really great ideas on the internet on how to do this. Good luck to you.
Repair or patch all holes and sand to match wall covering, clean very well, paint (don't forget the trim), paint of repair accessories as needed. color coordinate or use a color theme for rugs, towels, soap dispensers, etc. add over the toilet shelving, put contact paper on the inside of medicine cabinet, install a pull out drawer under the sink in cupboard, paint cupboard, install new shower curtain, add shower or bath storage, add some artwork, etc.
31 cheap tricks for the bathroom:
Start with the walls, choose a bright fresh color, paint the ceiling too! You can add crown molding to give it a finished look. Next the floor, if it’s real ugly cheap linoleum, but in decent shape, get stick on tiles to stick over existing tile. Lighter and fresh looking instantly! the countercan be painted, be sure to read up on how to do it correctly. So it doesn’t peel off. You can purchase new fittings, towel bars, faucets. Have an ugly mirror cabinet? Remove it, and put in a beautiful framed mirror. New towels to coordinate/ compliment the colors . New light fixtures. And art!!
Here is how I updated my small bathroom on a budget https://www.homeroad.net/2018/04/a-neutral-bathroom-makeover.html
Here's our small toilet makeover, n a very small budget https://vickymyerscreations.co.uk/thrifty/bathroom-decor-have-thrifty-fun-styling-your-small-toilet/