Had to do that from Zeebrugge to darkest Norfolk years back when my clutch cable broke in the middle of the night. Including on and off the ferry (would have been buggered if I’d had to stop on an uphill though). You need a strong battery to start the car though (put in 1st/2nd - can’t remember which - and turn the key)
But back to the OP, if you can press the clutch you can cycle. Just get a click pedal for the right foot if you haven’t already got one.
Nope. If you don’t get the revs correctly matched it won’t normally let you engage the gear. As long as you’re gentle it’s not that hard. I do it all the time (well not literally) on my Land Rover.
Learned the skill on motorbikes, where it’s a lot easier, and one could literally only ever use the clutch to pull away. Had a clutch completely fail one time and rode it around for a couple of days, avoiding stopping wherever possible and bump starting it in 2nd when I needed to. Not ideal, especially in traffic, but needs must, and when you’re young…