Starting African peacock cichlid tank

[Jessiknox]

I just bought and set up a 36 gallon bowfront tank and want to know how many I should get. I don’t want too many since I heard it will overload my tank water nitrite levels and I don’t wanna have to do allot of water changing but also don’t want territory issues. I want something simple with not allot of work. I have one filter hanging on the back of my tank. How many fish would you get at one time and how long until I put my next batch in? A week or two? Will I only need 1 picasimus and 1 clown loach? How often do I feed and how much? How long between water changes and is it 10% water change? We have reverse osmosis. Would it be best to use that for the water changes?