Hi Chris, and welcome to the forum.
You've come to the right place because there's a ton that we learn from one another on this forum. It's true that garters are brimming full of personality, but the first concern for a wild garter is not to stress it out while it's adjusting. Garters (and snakes in general) don't show many signs of stress or even injury until there's a real problem. While he's accilmating, I'm sure you'll enjoy reading some of the older threads that talk about the needs of a new snake. Be sure to use the "search" function to find whatever you want. It's just below the "forum" tab near the top of any page. Have a great time learning all about your new pal
Rick