• Benchmark -> there is no set benchmark. Just keep learning. Learn as much as you can.
• less free time -> this is not something you should be saying but I understand due to all the assignments, useless record work etc. Try to finish all of your college work before-hand and not procrastinate till the deadline. Follow the principle of eating the frog first. Google what it means ;)
• HTB -> don't start with this. I haven't even created an account there yet.
• The thing with security is, you need to learn those skills which will get you hired. No one is going to hire you if you know how to break Linux machines. Learn how to defend machines. Learn AWS cloud security. Get AWS Certified. Learn CI/CD security. Learn things which will get you hired.