Before getting started in judo…
Judo is a traditional Japanese sport/activity. As such much of the rules and customs are in traditional Japanese fashion. Respect will be of the utmost importance. There is a hierarchy of respect that should be observed.
As with any new physical activity you may decide to undertake, initially here may be some discomfort on the part of you body as you may be using muscles that you may not have used in a long time, or never. This is a natural occurrence and it will pass as a step toward a stronger healthier you.
Keep in mind the goals you come in with. There are many different levels of Judo from casual exercise to international competition. The demands on your body and time should be allotted accordingly.