I have been drinking protein shakes on and off for 40 years and since I started in weight training 2 years ago - drink one every moring.
Protein is the item that builds and repairs muscle - now having too much will not harm you in any way - what will happen is if you have way too much then your body will just expell it as waste.
Can you get fat by drinking too much protein - as with anything that is eaten - your body only required so much to keep it going, if too much is ingested then it's turned into sugar, then stored as fat and eventually eliminated.
If you are not real active then only have what your body needs and this is done by how your muscles feel - if they feel kinda sore then you need more - if they are relaxed at end of day then your taking in right amount.
You have to be the judge of this.