re: Is there anything that I should know before trade school?

Good for you. Trade school / community college tech driven is a great thing. You will get your foundation there. You will also learn a lot where you decide to go to work. No matter if it’s refrigeration / process tech / electrical / E&I / automotive. I’d take advantage of the associates degree if afforded that opportunity at your school of choice. Can be in your hands in 2 years.
Once on the payroll, attitude and work ethic is everything. Stay positive and do the right thing. Doors will open. Whatever you are hired for, do that thing well first. Doors will open. Best of luck son.