Before you ride check the following:
1) tyre pressure - your bike shop will explain the tyre pressure for your bike. You will over time adjust the tyre pressure to suite your needs and the terrain being ridden.
2) Lube chain - again your bike shop will advise on kinds of lube and how often to lube and how much.
3) Check wheels turning freely and brakes engage and release.
4) Ensure the quick release skewers for your wheels are tightened.