A looooong time ago I learned to drive.
Figuring out the clutch was just a single driving lesson. He took me to a road which was basically a long hill with no traffic around. He got me to head up the hill in first gear, then to slowly start depressing the clutch until we stopped moving. Then he got me to just play with lowering the clutch more (we slowly start to roll back), lifting the clutch (we start to crawl forward), adding some more throttle and then catching and holding it on the clutch again, rolling back slightly, crawling forward slowly, and again, and again - all while listening to the engine note so I could hear just before we stalled. We spent about half an hour on that hill and by the time we left it I had pretty much mastered holding the car on the clutch.
Just remembered another thing he taught me which should help with standing starts.
Doing a hill start, you pop it into first gear with the clutch down while still on the hand brake.
Give it some revs (not a huge amount, and how much exactly will come with practice) and slowly start to come off the clutch. What you’re looking at is the front of the bonnet. As you get to the biting point the bonnet of the car will lift slightly. At that point you should be able to take it off the hand brake without rolling back.
Same thing if you need to do a standing reverse start on a slope, only this time you’re looking for the bonnet to dip a little.