I'm going to date someone I didn't have feelings for so I wouldn't upset them
Why wouldn't you just tell them you don't like them?
Truth is I'm just too shy to admit I don't like them
You being shy is unfair to this person. You're making them think you're interested when that isn't the case. Just be honest instead.
Truth hurts so I'll continue pretending I like them until they leave me.
I really think you should just be honest with this person. I know it's hard but at least this person would know the truth.