The Sig Cub is a kit. It comes with all the wooden parts to make the model and a few hardware items.

It will not include things such as glue, coverings, fuel tank etc. It is a kit so you will have to build it yourself. The Sig kits are 'proper' kits so will take quite a while to build but should result in a nice aircraft.

They are not painted, they are not even covered. They will need covering in a traditional material and dope, or much more commonly these days a heat shrink fabric or plastic. It will obviously not come with any radio system or engine.

The cub looks like an easy plane to fly, and in the air it is. They are a little tricky to take off due to the tail dragger configuration. Not ideally suited as a trainer (but a lot better than the P51)

This is a completely different airplane from the ARF trainers that you are looking at. Please do not rush out and buy something. I know it is tempting (I have kits sitting in my room at the moment that I have bought and not got round to building). Make sure that you know exactly what you want and then, and only then, go a buy it knowing that you have exactly the right thing.

I have seen your other posts and know that you are looking into visiting a club. I would suggest that you don't buy anything until you have spoken to them. They will advise you on things like, which manufacturer of radio to buy and what mode (whether the throttle is on the left or right stick). If you get these wrong then you may struggle to find someone who can teach you to fly.

They will also have particular favourite models. I am not suggesting that you should buy what they tell you, but listen to what they have to say and then make up your own mind.

You are going the right way by asking questions here. Just hang on a bit longer and it will all be worth it in the long run. I promise.