It depends what insulin you're on and what your blood sugar is before eating. Also, when eating out the food can surprise you sometimes and be less or more carbs than you think, or even be delayed.
Personally, if my blood sugar is in range, I'd probably wait till the food was in front of me. Also, when eating out we tend to eat slower and chat, so that offsets having the insulin just before eating to a certain extent.
Hi @delmcp Welcome to the forum...glad you're off to a good start...keep up the good work
In response to your question...eating out is a tricky one...agree with everything @azure said...it's a learning curve and something you will probably never get right because there are too many variables...in a chain restaurant you can pretty much guarantee what you're going to get each time but anything outside of that it may not always be as expected...or on time...so injecting ahead is not always advisable.
There is so much to take in post diagnosis...it can take a while for everything to sink in...be kind to yourself and give yourself time to get your head round it all.