Congratulations!
Yup, totally.
I just started my MA in Environment and Management in September. My program is for working professionals, similar to yours, except we have three, three week residencies in October (in Victoria, B.C. - I just got back two weeks ago) and my course design is predetermined so it fits into a two year program. The way it’s designed means that this semester I had three courses at once. I work full time as well, so during pre-res, I spent maybe three evenings and about eight hours on the weekend doing readings and assignments, and thought that was tough! Oh how wrong I was! Ha!
Res consisted of classes from 8 - 5 Monday to Friday, then group work from 5:30 or so until 9 or 10pm, and 10 - 15 hours a day on the weekends. It was nuts, BUT it was my only focus, so it was ok. However, it sounds like you’re not doing in-class stuff, so you won’t deal with that.
Now that I’m post-res, I’m working a LOT harder on my assignments. I read textbooks/literature on the train to and from work, read or work on assignments during lunch, and I am doing homework almost every night for at least 2 - 3 hours. On the weekend, I’m putting in about 20 hours total. I have no social life right now and don’t really do anything fun. I don’t have kids, and my husband has taken over household chores for now. But keep in mind I’m doing three courses, so if you are doing one, or even two, your workload will be much less.
I’m assuming you will be writing a thesis? If so, and they don’t require any grad level writing courses, find one and take it. We were required to take Analytical Thinking and Communications this semester and wow, my writing was WAY below the graduate level. Plus, learing proper citations (which depend on your University - we’re APA 6th), learning how to structure arguments (which feeds in to your thesis), learning how to read the literature, etc., are all really, really important for a good grad school foundation. Also, you may want to check out the timelines and guidelines for your thesis now. I don’t have to submit my proposal until May, but before I do that I have to do about 1/3 of my literature research, find a supervisor (check on your thesis panel process too - some Universities assign them to you), and write and refine my proposal.
Question, question, question. If something isn’t clear, ask for clarification. Always read ALL the required readings, and try to get to the supplementary readings. Consider making notes rather then highlighting - I am finding it much easier to retain information through writing, and it’s also a good way to summarize and highlight key information. If you’re having trouble with parts of a course, your classmates might be too, so see if you can form a study group. I found that group work really helped everyone understand all the material because one person would know a bit about this, then another a bit about that, and we were able to figure it out together.
I’m not sure how grad school compares to undergrad (never been), but others in my cohort say that it’s much more strenuous. That said, if you keep focused, and most importantly, have the support of your family, you’ll do fine.