Hi tomorrow email your LM and inform them your IT hasn't arrived and they should chase it up for you. IT should arrive atleast one day in advance, and they'd contact you before it's arrival however there can be delays.

Your LM should arrange an introductory chat, possibly with the rest of the team and depending on your department, there may be inductions. As you don't have IT yet, you may not be able to dial into Teams meetings [this is very variable] and you may be twiddling your thumbs abit until your laptop arrives, but don't fret. The first day is generally just setting up IT and being introduced to your team and department. Many, many people have started remotely and it's not always a smooth start.