+1. Reddit is not a good source. This is the best forum for your fish. Other good sources are fishbase.se and seriouslyfish. A good starting point is AqAdvisor. As for your Senegals, they should be good in your tank size. I would suggest a wider tank, but I understand financial problems and how frustrating it is. You can keep them in that tank long-term, but can also upgrade to a larger tank. Potential tanks include 55g acrylic, which is 15" wide and 18" tall (I have this tank), a standard 75g, which is 18" wide and 20" tall, and the tank I have currently, a 90g wide tank, which is 2'x4' and 18" tall. The larger and wider you go the more species you could put in. If you go to a 55g, perhaps you could try your hand at a Delhezi (which is a really active and rewarding fish). At 75g you can try some of the rarer species. Mokelembembe, Polli, Delhezi, and maybe palmas.
Pellets are staple for food, as Deadeye said. As a juvenile, my del loved Brine Shrimp. He is not a fan of Hikari Sinking Cichlid Gold I give him now, but still eats it. As they get older you can start to vary their diet with fish fillets or market shrimp.