Spend a lot of your time on building your resume! Give it for a review to everyone: your Co-op advisor, friends, family, cat, dog, parrot, a random person on the street...well, animals are exaggerated but literally to EVERYONE! The more different perspectives you have the better your resume will get.
Imagine you've got an interview (you will get it, eventually, don't worry). Don't be nervous at the interview. Employers are just people who want to hire the best fit for their company, they don't bite. Right before the interview, I like to say to myself "I am going to speak with a friend whom I haven't seen for 10 years" multiple times, so it's really stuck in my mind. Then, the interview goes on a positive note - employers value it. Moreover, when you are positive, your answers to the behavioral questions get much more interesting, and solving technical problems gets easier.
For Celayix Software specifically, solve as many "Leetcode" questions as you can and review relational databases. Can't say more about the interview process - military secret ;)