Here is a simple, fast beginner friendly servitor that will do it for you, but I recommend finding a banish ritual that works for you, for long term use. Preferably something you can commit to memorizing and using. I personally use Ben Woodcrofts, from Angelic protection magic, though most people around here swear by the more complicated LBRP and various versions of that.
As far as shielding and warding go, you can use the search function to get ideas on that, or google psychic shielding/warding and there are lots of resources on it 