Since you're an adult, you should have the necessary discipline to keep up with your studies in trade school.
When I went through the 4 year apprenticeship school in Denver, we had school once a week for 4 hours. Then you had approximately 6 to 8 hours of homework for the next week.
Many people get bogged down trying to memorize everything in the text they're reading.
I would recommend that you get a book on how to study. It might sound crazy, but you learn to highlight the points you need to know instead of trying to absorb every little bit of material.
Another thing is to keep good notes when the instructor is lecturing. I think the most value I got out of trade school is getting another viewpoint from people in the trade, not just the shop you work in. It gives you a great pool of knowledge to draw on!
Again there is a science to taking notes, you don't try to furiously write down everything the instructor says, you write down highlights.
Again congrats on going to trade school, make the most out of it and ignore the whining babies who want to get out of class early and go to the bars. I always tell them that there's openings for drywall installers if they don't want to learn the electrical trade.