Make us able to reward Roblox Players UGC from objectives in-games

Lf someone to help me script this thing. I don’t know how to script D:
I want to make a timer or a GUI which shows time.
I’m currently making a backrooms game and I’d like to make a timer which starts from a set time.
For ex.
Let’s say I want the time to start from 1pm. If so ,then I’d like my clock or timer to say it’s 13:00:00 from the start of the game and function as how a normal clock does. I would like to show the minutes and seconds. My game’s solo player and it would really help if someone cooperates with my problem

Sorry for bad grammar guys.