might be the wrong forum but heres my honest answer.

no you do not need to be good in drawing to learn graphic design. it helps, but not a requirement. whats more important later are the skills in photoshop/illustrator/etc.

that being said. advertising is more of the big idea, excecution, engagement, human psychology, marketing, and invoking emotions.

i did a degree in business over 10 years ago. in my spare time i learnt from online tutorials and did design in my spare time. i joined the advertising industry after my 1st job in a bank.

TL;DR, doesnt matter where you study or what you study. as long as you have a good portfolio. i'd suggest asking what coursework you will be doing throughout your course and if it will help you build a better portfolio of work.

hope this helps. (: