TRX you have a nice tank. I get the feeling you are looking for a peaceful reef setting.
I think the rock is a great start, the first step, and the most important is the cycle. You must be patient. You need to get your beneficial bacteria up to par whereas any addition of ammonia, and all life expels this at different levels is quickly consumed. Without this, or, without a strong export function will just lead to big losses.
If you like clowns, (I started with a pair of black Darwins) or ocellaris pair might be the first big addition to your tank. Once these settle and you have a command of water parameters (NSW reccommended) in a few months, add a BTA. You will need at least a 165w LED light, these you can see on Amazon for 150 bucks and consistent water to support him. The
Reason I put him next is he will wander for some time until he finds a place he likes, avoid moving him to the Centre, he will just move wear he wants, but at on point he will stop.
During this time you can add a royal gramma, and or a purple or red firfish as an example.
You can probably add a ton of corals if you want, but add slowly everything so each time your bacteria can catch up to the new processing level.
I would forget SPS, and suggest a Softy/LPS mixed reef, lots of choices and colour here.
Watch torches, Favias, and anything else labeled agressive as they can shoot out sweeper tentacles to kill neighbors, they are OK, but must have lots of space, which you don't have a lot of.
Always run carbon and get your nutrients down to 2-5ppm nitrate and .02-.04 phosphate.
So, to sum up, get Rock, cycle to ammonia is zero, add some food, ammonia must stay zero, add say your clowns, wait a month, make sure all three are in the stated ranges, then add slowly.
Good luck, your on the right track...