The first couple will do. This is asked a lot.
Not sure what you mean. You get a text menu and arrow and enter through the choices, occasionally filling in some text boxes.
Boot floppies are for people who can't boot from CD. If you can, you don't need them (to install, though having them around is nice for emergency boots) and if you can't, then that's how you boot the box to start the install.
Do a lot of searching here if you have more questions or problems. Happy to help, but Slack's not usually very hard to at least get on there and most of the common issues are well covered here.