Okay. Assuming it's the clutch (which I don't think it is but...)
Driving without the clutch.
If you have some clutch use, you may be able to start the engine and use the clutch to get into first and move off. If you have no clutch at all, turn the engine off, put the car in first, turn the key - you should be able to start the vehicle moving and then the engine started on the starter motor.
Use any trick you can to avoid stopping - when my Fiat 128 broke her clutch cable, at one set of traffic lights, I did circuits of an adjacent petrol station
Changing up gears is easy. Simply lift off to remove the pressure on the gears, slip her into neutral, use the throttle to lift the revs to where you think they should be (or just blip the throttle) and easy the gear lever into the next gear. After a couple of tries, you'll learn to judge this so you get a quiet and smooth change.
Changing down is the same, but you need to lift the revs higher and need to be more accurate judging them. Best done when you're right at the bottom of the rev range.
Using a bit of mechanical sympathy, it's surprisingly easy to drive a car smoothly without a clutch and you'll do no damage. It's constant rough changes that do the damage.
EVERYONE should practice changing up a gear without the clutch. Just a few times to get a feel for it. You shouldn't
have to do it but when you're forced to is not the time to learn. In my 40 years driving, I've been forced to do so four times. My first MGB tore the lining off her clutch (hard start at a hill climb
). A year later, the roller bearing thrust washer they fitted seized. My Fiat 128 sport broke a clutch cable. My son's Mitsubishi Cordia had the clutch pedal pull out of the pedal box when he put his foot on the clutch. It happens. Of course, other people will never have a problem.