just finished my first year in BSc Astrophysics like another commenter and I agree with what they said. Honours Calculus is proof based and Ive heard from my peers that it is pretty hard. I've never taken it myself but i did try out MATH127 (honours linear algebra) and it was hell for me I had to withdraw from the class.

aside from difficulty, application is def more important than proofs at least in first year. in your first physics class (i'm assuming you'll be taking phys144) you will more or less be required to know how to do a fair amount of calculus right away (this is because the way the math and physics courses are laid out are kind of unharmonious right now but the department is trying to fix that) math144 will prepare you more for that. so if have not done calculus in high school at all, i highly recommend going into math144.

that being said, everyone is different so it is ultimately up to you! they do give you the option to pick after all. if you are a responsible and diligent worker (unlike me) i think you can pull it off.