Hi NaeNae
You have just had major surgery; you can expect to have some pain for the next few weeks. Bleeding can continue for up to six weeks. If it is sore when you poke under your belly button then don’t poke it. (Sorry could not resist that). When you have a CS your insides are bashed about quite violently, it is quite normal to have pain like you describe.
You can have a bath at any time it will not do you any harm.
It can take a long time for your belly to get back to normal.
You use your stomach muscles a lot more than most people think. When getting out of bed or up off a seat you put a lot of pressure on these muscles. The amount of pain you are feeling should start to reduce over the next week or two.