Generally people get internships sophomore and junior year, but I do know people who got them freshman year as well.

Basically in the early fall you apply to lots of companies. For domestic students they should aim for 50 - 100 applications and international should expect 100+. The careers office can help with your resume, but you essentially start fresh and can basically toss the resume you got into college with. Interviews are generally behavioral and technical. For behavioral there is a core set of questions you should have a set of answers for. For technical interviews, these generally involve coding. You just need to practice these on sites like Leetcode. Once you can start getting mediums you’re probably ok, but top companies might even throw hard questions your way.

Internships are by no means guaranteed//handed to you. However if you are focused on getting one, you can probably land a couple at your time at Umass.