LA in mid-June is nice and warm during the day, but cools off at night so consider bringing an extra layer you can throw on once it gets dark!
The LA River Center + Gardens has free on-site parking if you want to drive, but rideshares are also readily available. If you're going to get your drink on, just get a ride! The River Center is right by Dodger Stadium and lucky us–there's a home game that afternoon. Please allow time for some authentic LA traffic when traveling to the ceremony.