I've got my moles removed by plastic surgeon 2 months ago, they left red scars that are fading, how long does it take for them to be unnoticeable?

Scar. it takes a full year for a scar to mature. It the scar continues to be red or elevated, have your surgeon evaluate it.
Scar maturation. Each individual has their own scar maturation rates. Asa scar matures the color lightens from red to pin to nude or skin color. There are many scar remedies that all work so ask your PS which you should use.