Hi
Well, I have little experience with shared hosting since I have the luxury of root servers (VPS and dedicated). But there are others in the community who do.
The basic question is though how big, how active is your site? The total number of users? The max. number of users logged in at a given time (last 5 minutes)? What do they do? Do they chat https://docs.moodle.org/en/Chat_activity or take synchronous on-line exams https://docs.moodle.org/en/Quiz_activity ? If so how many at a time?
Go through the documentation at the top of this forum, https://docs.moodle.org/en/Performance and https://docs.moodle.org/en/Performance_FAQ.