Complete confusion in loop

I am trying to make a quiz program

I have a loop running which takes user input compares with answer if it is correct rewards point

there is also a timer running

but till the time user does not input anything the code doesn't move forward and so i cannot check the timer.

Please provide any idea as how to check timer and also keep checking for user input

I dont know anything about multithreading

I am using C

Please help