2006 Barina manual. Driving, suddenly clutch doesn't engage on take off. Waited and then it grated and worked. Temp of car suddenly rises, air con then blows hot air. Stop, engine super hot

The only scenario that i can think of that could create all of your issues is your clutch is and has been slipping for some time. All other train of thoughts really don't make sence. This would give issue either selecting a gear whilst driving or possible slecting gear and engine speed raising but vehicle not moving from a stand still start on sharp pull away. Engine speed would be running higher than required most of the time which would increase engine temp considerably. Due to extreem engine temp your air con would probably switch off as to not put additional load on your engine creating even higher tempratures. My advise is It really needs a visual / test drive to confirm a diagnosis by a qualified person for this information to be confirmed. I hope this makes sence good luck.