Most ED Cmdrs are friendly and helpful, however, as in many games, you will come across Cmdrs who like to kill other players. This is part of the game, so knowing how to escape them easily is useful at an early stage of your career.
If you are interdicted don't panic, submit to the interdiction by throttling right down (this allows your FSD to recharge faster), you then throttle back up and boost away from your attacker. Continue boosting until your FSD is charged then wake out of there. During this encounter I usually have four pips to engines and two pips to shields, although some other players balance their shields and engines differently. When you are new to the game, and have a small weaker ship, it is better not to engage in combat, more experience and ship upgrades may change your tactics over time. I know this all sounds complicated but it's quite simple really and once you master it it will consistently save your life. Stay safe and enjoy Cmdrs.