Imagine that you are approaching a black hole in a spacecraft. what would you see? what would happen to you?

As you approach the event horizon, your body would be pulled towards the black hole. It's a process called sphagettification.

Here's a quote from an article explaining this.
And gravity from the black hole is starting to pull on your feet more than your head. "The gravity wants to sort of stretch you in one direction and squeeze you in another," says Joe Polchinski.

As for what you see, that is hard to explain without showing a video, at least for me, but you would see this black hole (ha) and whatever is outside starts to flatten and condense (from your POV) then you would fall into the black hole and then it's complete blackness.

But all of this is just educated guessing, and honestly, you'd be dead before anything would happen.