Well, since I saw your post only today (5 Oct) I am assuming that your BA is 7-8 Oct, correct? Where is your TPU?
I would hope that you got a welcoming email from your CO? If not, once you arrive, hopefully before morning formation, you could seek out the unit administrator and find out who will be your mentor. I would suggest you arrive NLT 0730 hours (NLT=No Later Than)
I can remember my first BA. at that time I hadn't yet received orders to attend OBC and I knew nothing about Military Custom and Courtesy. When you took your Oath did you receive the handbook: Army Officer's Guide? 50th Edition. LTC Keith E. Bonn, USA (Ret). Stackpole Books. You can find it at Amazon
.com The ISBN is: 978-0-8117-3224-6. You can also check it out at: www.stackpolbooks.com
. It cost something like $25.00 USD
Another good reference that you may find invaluable is:
Army Dictionary and Desk Reference. 3rd Edition. Major Tim Zurick, USAR (Ret). Again from Stockpole Books. Around $17.00 USD. ISBN: 0-8117-3154-5
Remember to salute anyone higher in rank than you. Wait for them to acknowledge you - they will return your salute. Hold your salute until they do. One big mistake I made on my very first day was....I called the SSgt "Ma'am". Gulp, didn't do that again. At least she understood that my Mum raised me to be respectful.
Oh, another suggestion (given with the best intentions): memorize the different insignia of Rank: www.goarmy.com/about/ranks_and_insignia.jsp
Try to make the best of your first BA. If you can keep us posted on how things went for you!