Hmm, there's a LOT you can do when you have a fresh start like this - Go and read through a fishless cycle where you cycle your tank with pure ammonia. after that, you should plant your tank.
You shouldn't really have your tank in direct sunlight so either find a new spot or cover it.
I like to put sand as my substrate with rocks and driftwood.
After that you should try fish like Bettas, Mollies, Tetras, Platies, Guppies, Barbs.
Definitely have a Pleco or two in your tank just because they help with the maintenance of the algae and they're just really cool in my honest opinion.
Once you've had those fish for a good long time - few months to a couple of years, you can move on and explore the possibilities of other fish species.
I should also add, is that you do water changes every day, week, or two weeks - I do mine everyday just a little bit so it adds up to 50% of the total water at the end of the week. But it all depends on how many fish you have in your tank. Tell us what fish you want and how many so we can help you in what percentage you should be doing everyday or weekly
Hope I helped, and welcome to the forum