They all mean basically the same thing. However, "We have rapport" is usually for business-type relationships, "we hit it off/click" is usually for people you've just met (making new friends, etc.), and "we get along well" is more general. Hope this helps :)

Hi Ethan, “We hit it off/click” means that some people who just met for the first time, after interacting for a little while, became friends immediately. If it’s a romantic situation, it means the couple liked each other right away. “Get along with sb” means that you are friendly with them. Whenever you interact or hang out with them, you agree on a lot of things and there are almost no disagreements or issues. “Have a rapport with sb” means that you don't know someone very well, but every time you’ve interacted with them, it was a positive experience. I hope that helps!

"Get along with" means you and another can happily spend time together, like as friends. "Have a rapport with" would typically be used in business to say that you and another have created trust with each other. "We hit off/clicked" would usually be used after meeting someone new when the meeting went really well, you liked each other and got along very well from the start.