What do you believe will work best for you? If you believe you are able to handle taking a majority of your classes in the morning to have more time to study or for free time during the day, then do so, vice versa. Personally, In undergrad, my first semester classes were already prescheduled for us and it helped me figure out how I would like to adjust my schedule for the next semester. I based my schedule off of my sleeping pattern, my study time, my social-free time, and my work time. It then allowed me to design my schedule in the way that I saw fit best. I choose to do some classes at early in the morning and others later in the afternoon on certain days only. Do not be afraid to reach out to your advisor. I am sure they will love to help you with your schedule as well.