This can be done with high grades, certifications, or experience. The best jobs are fewer in number, and you want the best. Brush up on your basics and be ready to answer the technical questions. Certification is important. Degrees are important.
Grades are important.
Resumes are important. Interviewing skills are important. Technical interview answers are important. All of this is true, but the gold standard of the tech and network support industry is and always has been experience. Now that some are being laid off, employers looking for help are more likely to insist on experience.