Reef Tank Questions

Thinking of starting a Reef Tank…Help Please!?
I saw a Reef Tank at a local pet store and I was thinking of starting one up myself (seems like a cool hobby) anyway I’ve done some research and theres some things I’m not quite clear on so bare with the questions…
1. Is a 12 Gallon Nano Cube tank good? I know beginners are supposed to start with a bigger 55 gal tank but there are 2 problems, no room and It’s my understanding the Nano Cubes come with lighting filtration on heating is that correct?
2. How do I clean the tank and how often?
3. How do I do a partial water change?
4. What Live Stock? so far i was thinking Fiji Live Rock, Live sand, Coral: Branching Frog Spawn, Blue Mushroom, Emerald Crab, decorator crab, skunk cleaner shrimp, fish:Brown Gobbie, Green Chromis, Blue Damsel
I know I have a lot more research to do before I start this, consider this a rough draft but give me some suggestions stuff I should add or change. Keep in mind I can only do a 12 gallon tank tho
Thx
If you have never done a marine tank, especially a reef tank, do NOT start on a 12 gallon nano reef. They are by nature not very stable due to their size. When something goes wrong, it will go wrong very quickly. If you have to ask how to do a water change, a nano is not for you.
I strongly recommend that you wait until you can do this right.
Nanoreefs are NOT for beginners.
Jewel 180 Rio Marine Reef Tank