Just bought a used 55 gal fish tank

So I just bought a fish tank that was used for a freshwater tank.

I've been looking into this hobby for a couple of years, but I took some time off of researching so I don't know what is good anymore and just forgot some things so I'm looking for some guidance.

1) How should I clean the fish tank? It is filthy so should I give it a vinegar bath?

2) I plan on having some fish, shrimp, and corals in the tank, not sure what kind of fish or anything yet.

3) Here is the list of equipment that I have written down, just seeing what I missed:

T5 Fixtures (Not sure on bulb type)
Protein skimmer (Not sure on brand)
Powerhead(s) (what GPH should I target for)
Thermometer
Hydrometer
Test Kit (ammonia, nitrite, nitrate)
Live sand
Live rock/base rock (not sure what I should go with here)
Sump (looking for opinions on size and how to make one)
RODI system (i've seen a few online and have read the sticky on the forum)

I'm sure there are links that explain these items more, but I am looking for direction on where to start reading or inputs with experience. Based on my goals for the tank, what would be the best things for me?

I plan on cycling the tank with just the live sand and the rock I choose.

Thanks for all your help in the beginning of my hobby.

 

I would give a vineger and water bath, some may even suggest bleach.
As far as you other equipment goes are you planning to do HOB or getting a sump?
you could make a sump out of a 20g tank, and some plumbing.

 

I would say avoid the live sand, the amount of bacteria in the sand will do very little to help you cycle. Buy mostly dry rock and a few pounds of live rock to start your cycle.

Buy a 4X54W T5HO fixture with individual reflectors or a formed reflector at the least. I suggest getting ATI bulbs, they have the highest PAR ratings and are very reasonably priced. Get 2 Blue Plus, 1 Purple Plus and 1 Aquablue Special. The Aquablue is a white bulb.

 

What does HOB stand for? I was thinking of just buying an overflow box or buying a wet/dry filter and converting it but these seem expensive to convert to a sump when you can make one yourself.

2in10, thank you for the help with the lighting!

 

HOB is hang on back, i suggest going with a sump just IMO, but if you diside not to you could get a HOB skimmer and filter. many people are going both ways.

 

I'd rather just invest in the sump right away and not deal with the HOB options