Need advice *long*

I’ve been in a relationship going on for 5.5 years now. We were highschool sweethearts and have dated since i was just shy of 16 years old. We are both 21 and 22 now. We have 2 children together, a 2 year old and a 7 month old. I have always thought about going back to school, before I even graduated I wanted to go to college. I just was never sure of what major I wanted to take. In 2016 after I graduated highschool, I took testing at my local community college to get started. Well shortly after that I found out I was pregnant, so I put school on hold. I got lucky enough to work with his mother at a salon and am still working there. Since we have 2 children, I only work 10 hours a week and am only making $12/hr. I feel as if I am stuck and am not able to do anything. He makes enough to pay the bills but I feel like I’m getting nowhere. I cannot get anymore hours and am looking for another job. ***He doesn’t agree with me wanting to go back to school. He says its a waste of time, when I could be working and making money instead.**** I don’t want just a job, I want a career. I want to be somebody and do things. I have so many goals and it feels like he doesn’t have any. We both want to buy a house one day and buy better cars. I just wanna be the best mother I can be and do everything for my children. I want to take the next step but he thinks its not a good idea and not good timing. What do i say? We had a giant argument about it and it never really resolved. We don’t see eye to eye on these things. He got frustrated for me even bringing the topic up. I never made the decision, I was just trying to map out the unknown of the future. I want to make more money and be able to reach my goals. I cannot do that if i stay where I am. How do I make him understand and support me?