Good for you! You just took a big step!
My advice is to just get on with your exercise and whatever eating plan you have, and then see how you feel about posting photos again in one month. You might be excited to do it...or you might decide to wait. You don't have to commit right now to that.
The only thing you have to commit to right now is real change!
I didn't post any photos until I was 14 lbs from goal and had already lost 63 lbs. But I had taken some photos after 49 lbs were gone, so I had those photos to post at the same time. I found it pretty satisfying to post several pictures at one time that showed a steady progression.
But everyone is different, and you might like to show pics more often.
Best of luck to you!!