There are two systems at golf clubs. One has a booking system, BRS seem to be the most common provider of this software. All tee times are shown, you book your slot online or ring and ask your club to do it. Once that time is booked it is yours, no one can jump into it. You can book days in advance or minutes before if a slot is empty. Most clubs have a booking system now, it is perfect for the phone / computer age.No tee times? I am new to the Sport but as a member you can finish work and just roll up and play?
The other system is one where there is no booking system, you simply turn up, take your chances you can get out, wait in line. Some literally have queues of golfers, some have a chute where you put your ball and when your ball comes out it is your turn to go off. Clubs running with no booking tend to be quite traditional, members clubs.
I'll leave you to decide the advantages and disadvantages of both. It is a staggeringly divisive subject on here that never ends well.