glad to hear of the bike ride! congrats! hope to hear many more days. it will be hard at first not going to lie. maybe try like 3x a week (this is ambitious). be sure to stretch after your morning ride and after your afternoon ride. leaving 15 min sounds perfect for doing that. you need your body to stay limber so it's a good idea to take care of it!
sooner or later you'll be commuting everyday

welcome to the addiction