Hello I'm new here. I was looking for a nice goldfish forum community and this seems like it must be the place

I have this hexagon tank, it's 2 40 gallons with 2 tubes connecting them that I want to set back up. It's been in storage for about 4 years now.
I've only been keeping an oscar in my 50 gallon tank for about 10 years now, and it's a bit boring. I have missed my 40 gallons with goldfish.
Can I call it an 80 or 2 40's haha. ??
First thing first is that I need to pull it out and clean it all up. It has under gravel systems and biological systems.
I am tempted to try a planted tank, I have had really good luck with 2 I have setup for friends now, but they didn't get goldfish in their tanks. I know the tank will be healthier if I try live so I guess why not go for it. I guess I will invest in a canister filter instead of the under gravel system since that won't work with plants.
Do you have any tips for me?
Do you guys have good luck with live plants?
Should I try to buy smaller say...2 inch goldfish versus larger ones?
I have major algae issues, what types of snails will not breed and work with goldfish?? My bf bought snails and I laughed at him when he said they won't breed....and they aren't breeding. I'm perplexed by it! haha!
Looks like I need to go river rock finding!

I will show pictures when I have it setup!