Most students struggle with time management, and therefore, health. Your body and brain need sleep. You cannot sleep if you do not manage your assignments and projects effectively. If you are sleep deprived, you are more likely to get sick and require time off. I encourage you to make a working schedule and stick to it, and if you are up for it, to make time to exercise in whatever way works for you.
Mental health is also often adversely affected during graduate school. With pressures so high and deadlines so short, students often abuse substances or fall into unhealthy habits. I encourage you to find and use any resources your school provides for maintaining mental and physical health.
Last, many students struggle with the job search at the end of graduate school. I encourage you to start making connections and going to networking events like it is part of your job (because it is). You never know which connection could turn into employment. You cannot always rely on your resume to get your foot in the door, so use whatever resources are available and get every advantage you can. Start looking for internships or employment a full year in advance. Other students or even the school itself may discourage you from starting so early, but you stand to benefit from your efforts... and they do not.
Good luck in graduate school! It changed my life for the better, and I hope it does for you, too.
The first critical area is introspection as to why you are pursuing a graduate degree and what you hope to get out of it. The upfront investment in determining what program is best for your situation is one of the hardest parts of the process. You'll need to determine full time/part time, affordability, competitiveness of application process, diversity of student body, GMAT scores, program ranking, and many other factors in narrowing down a school and program that will work for you. The legwork will make sure you are well prepared for the commitment needed if you decide to pursue, but will also require you to really think about what will help you meet your career and personal objectives.
The second critical area is being deliberate with your time in school. Once in school, the focus shifts to what you want to get out of your time therel. Assuming graduation is a given, you'll need to determine how you spend your time including school work, career and social clubs, networking, engagement with faculty, and time for fun. The formula that works for you will depend on your background, interests. and goals.
Finally, make sure you build your skills through a focus on your academics. Working effectively in group settings and finding classmates with similar motivations will help you with the academic portion of graduate school. I found I learned as much or more from my classmates and their shared experiences as I did from my professors. And that wasn't limited to their professional experience, but also the cultural diversity of the students. My choice of school broadening my exposure to careers and cultures which was highly gratifying.
I found that in grad school the expectations were much higher and more ambiguous than in undergrad. For my program, every course had a substantial amount of group work and coordinating among your team members could be difficult. Assumptions were often made that you already understood concepts, and the course work was to cultivate them through application. Many courses leveraged real-world work problems that we were expected to bring to the classroom for analysis. Also, in the last semester there was a capstone class that encompassed everything you learned in the program - which isn't terribly common in undergrad.
One huge benefit of grad school for me was making connections in the business world with my peers and professors. This wasn't only for job opportunities, but to share common problems, situations, and solutions across different industries. This helped me perform better at my day job.
If you are employed, you may want to inquire about tuition assistance - many companies offer this benefit.
Best wishes for success!
Think about what is the next step for your life and career. Do you want to pursue your interest in more depth or you want to make more connections in the fields that you are working on, etc. Why would you want to go to the graduate school and what you expect to gain and learn from it.
It would be difficult if you didn't do enough research about what you really want before jumping into the graduation school.