I love you /trek/-kun~

How do you deal with knee pain, bros? Power through it to keep the momentum / rest / any exercises to fix and prevent it in the future?
I started running 2 weeks ago, went 12km / 5:30 yesterday with a Running Club. After that my knee started slightly hurting when tensed and today I was limping on my way to the Running Club, so decided to skip it (no more runner gf for me).