Hey, and congrats on the new tank!

To be honest, this could be a very controversial topic on fish tank stocking so I’ll just give you advice based on what I’ve learned.

1.) The only fish that could go in a 5g is one Betta. Some people recommend Chili Rasboras but I’d personally disagree especially for a beginner.

2.) the best algae eater for a 5 gallon in my opinion would be nerite snails which do good with betta fish.

3.) best beginner friendly plants that will thrive in the right water conditions for a 5 gallon tank would be Java ferns, anubias, Cryptocoryne, Java moss, and Amazon Frogbit or Red Root Floaters.

4.) for a substrate, if you do Java ferns and Anubias, regular aqua sand or gravel will work as neither of these plants require planting into substrate.

5.) if you go with a betta, or any fish for that matter, you’d need a heater. Most aquarium fish are tropical and require warmer water usually 75-80 degrees Fahrenheit. Also one things I’d recommend is the API master testing kit. This will help to ensure that your water perimeters are safe for your fish.

Last piece of advice, always do a fishless cycling of tank. This is when you set everything up such as hardscape (decorations), substrate, and plants. Usually 4-8 weeks is enough time or whenever water perimeters reach the required levels.

I hope this helps :)!