The first thing you want to buy is a Park Tool Big Blue Book of Bicycle Repairs or something similar. Assuming the bike is the one in your link, you have mechanical disk brakes and the pads need to be inspected and the rear backing plate moved out to compensate for pad wear. Its possibly been 6 years since that was done. There`s usually a grub screw involved to lock the rear plate and
so the operation isn`t straight forward for a beginner without experience.

Likwise, instructions for adjusting derailleurs after the cables have been replaced aren`t included with any cable kits. Neither are instructions on removing the old cables initially.

The stand you`re looking at is pretty juncky and since this is the only bike you`re looking at - suggest you skip the stand and just find a park that has public bicycle stands. They may not be work stands, but if all you have to do is replace the cables and chain then you really just need something to hold the bike up while you`re doing that.

Cable cutters, a good file, cable lube, a chain tool, a set of allen keys and a No2 Phillips screwdriver should get you through that. A piece of cardboard to put under the area you`re working on will help find any small parts you might drop.

If you decide to tackle the brake pads - suggest you simply buy replacements and drop them in. On most mechanical disk brakes it`ll require pulling each wheel out alternately and backing off the rear plate to drop the pads, but then the new ones go right in. The only tools required are allan keys.