First of all Welcome.
Second it sounds as if you need to read up a bit .
What kind of tank is it , is it a JBJ nano cube , or an eclipse ?(elcipse will need to be moded more than the JBJ)
it is not that hard to do a smaller tank but you will need to take some time out once or twice a week to maintain it . It should only take maybe 1/2 hour to an hour weekly and that time may decrese as you learn what you are doing and how to do it .
I would say you could put a small occelaris clown or a perc in that tank , and maybe one goby like a yellow clown goby ,or fire fish .
You will want a CUC that will also help with your cleaning ... A good choice for a CUC would be a skunk cleaner shrimp , 3-4 small hermit crabs (red leg(4) and blue leg(4)) and a few no more than 3-4 nasserious snails ...
as for the cycle :
Ammonia will rise and fall to 0
NitrItes will rise and fall to 0
NitrAtes will rise and fall with your first H20 change
PH 8.2-8.4 Steady you dont want major swings tho there will be some with the cycle of the lighting .
Temp again steady . I run ours at 74*-75.9* cool with fans.
Spg 1.025 for reef .
To get the cycle started you can use your LR
aprox 1-1.5 lbs/gal
of rock is needed more if you go FOWLR
. you can also add an UNseasond deli shrimp into it to help kick start it . Please do NOT cycle with live fish . HTH