Macbook air activation error

Hi, i was wondering if someone could please help me. I’ve just brought a second hand macbook air 2017. Ive logged into iCloud and set it up however i’m trying to set up iMessage and FaceTime. When logging into my iCloud on FaceTime it says “an error occurred during activation. Try again.” and on iMessage it’s not even saying my iCloud is right. I’ve searched up why this could be happening and it’s telling me to go to settings and go to messages but there is no messages settings. Please can someone give me an explanation and some help.