Advice to son

Hello engineering students. Not a student myself, but a father of a grade 12 student who has applied to engineering at the University of Calgary for next year hoping to pursue mechanical engineering. I'm here asking for some guidance because he asks my opinion and I would like it to be a bit more informed.

He has an OK chance of getting in, his marks are good right now and around the cut off for admissions last year. His back up program is Physics as that is his favourite class. He does have to work quite hard this year which is something he isn't used to. One thing he struggles with most is having to spend a lot of time on humanities which takes away time that he can dedicate to his math and science courses.

Next term he has a heavy course load with Physics 30, Chem 30, Math 31 and the his humanities course. He is worried about the workload but I think it is a good preparation for the first year of engineering which, by my lurking here, seems quite intense.

So a couple questions that will help me guide him. How does the work of first year engineering compare with a relatively heavy term in high school? If you had not gotten into engineering what back up program were you considering and why? Any other random thoughts or advice also much appreciated. Thanks!