So I was planning to install a Nema 14-50 plug inside my garage and have it connected in there. I was wondering if I can have the tip left outside since I park outside and just have the wiring go under my garage. Will the rain damage the tip of the charger or anything?
Closing and opening your garage on the cable over time will break it. Leaving just the charging connector outside is perfectly fine, I have mine like that currently and it rains 24/7 here and I have no problems.
To solve the issue of the cable going under your garage, I would recommend you drill a hole through your garage wall, and place a trap-door to feed the cable through. This is what I have done, and I got the idea from this post here.