Tara, if you've got the will power, I'd say start today - and you know, even if you do start today, and you go to the party and cave, it's not the end of the world. Pick your self up, dust off, and start again. You'll do fine what ever you choose.
For me personally, I haven't had a drink in over 4 months - at first it was because of the meds I was on, now it's because of SBD. I'd rather have a 60 cal Hershey's Chocolate Stick than a glass of wine

But that's just me. I've also found that if I carry a bottle of water with me at all times, and a few packs of my fave water additive (FulFill - found at Walmart, or Totally Light 2 Go), then I can add those to my water, and have some flavor so I don't feel like I'm being left out - I'm enjoying my drink as much as the person drinking the soda or wine
Some of my fave P1 snacks/lunches and breakfasts...
Light'N'Fit snack size yogurt
BLT - no bread, and turkey bacon - just wrap the bacon and tomato in the lettuce leaf. YUMMY
Celery and Hummus
Lite String cheese
P2 - all the above, but I added a ww wrap with the hummus.
All this talk about hummus - and I don't have any

Look out Wegmans, here I come!!!! I need to pick some up on the way home!