Manual for a learner?

I (51m) now have 16yo learning to drive, and saving for his 1st car. He wants a manual, or at least how to learn, and my car is too highly modified to be a a “learner” car. I learnt to drive manual in a KE70 Corolla and a shitty Ford Laser 35 years ago. Is there anywhere I can buy a roadworthy, insurable beater anymore!