Nice looking fish!
Since I am not sure if you are looking for aquascaping critique or stocking thoughts I will give both
Thoughts on stocking:
The african cichlids and south american cichlids that you have generally require a very big difference in pH levels. What are yours typically at?
I'm not too well versed in african cichlid ID but the top right one is a Yellow lab which is a Mbuna. Mbunas are the bruisers of the aquarium world being both aggressive and tough. The yellow lab however is one of the most peaceful breeds of Mbuna. The other african cichlid could be a yellow lab hybrid but I can't answer that for sure.
The jack dempsey you have can be a hyper aggressive fish so I would watch for aggression as it ages.
The plecos are going to get much much bigger so be prepared to rehome them when they outgrow your tank. Some say they need a 125g+ tank to live in
But that 55g is a lot better than 95% of the common plecos are doomed to live in. Keep an eye on them as sometimes cichlids will decide to start attacking them and since the plecos are soo well armored the cichlids usually go for the plecos eyes. It doesn't happen all the time but on occasion it becomes an issue.
Thoughts on aquascape:
The substrate choice that you went with in the tank is really muting the colors of your fish and decorations, especially the dempsey. Black substrate w/ a black background is the most popular combination to make your fishes colors really pop out and be more vibrant. I used something very similar when I started out keeping fish, and since I tried out the dark substrate and saw the difference it made I never went back.
Some more caves might be appreciated by your fish. The african cichlids are both cave dwellers and the dempsey and two plecos would probably enjoy their own caves as well. Not too sure about the parrot.