Lots of answers to what is a perfectly reasonable and good question.
At first, I was nervous about the whole idea: how could I get the carb count right? Where should I inject and when? Would my meal be delayed? And so on.
Since my first outing post diagnosis, I've used disabled toilets to inject - but no longer bother. Although, because I don't get good reconciliation between my Libre and actual BG, I do sometimes find myself needing to wash my hands before finger pricking and establishing if I need a correction adding (or subtracting) to my bolus - so might use that time to also inject. But today I have no regard about whether a stranger might be watching me inject; nor whether it might offend someone.
When I can, if I know where I will be dining, I often look at the menu online and see if there are natural meal choices that I can estimate the carb count for. But this is far from foolproof; online menus change and sometimes preferred options are not available. Over the last 32 months I have become far more relaxed about estimating or just guessing what the carb count might be. Like
@rebrascora I rely on Libre to alert me if I've over bolused or to find out if I've undershot and am going high. And like
@rebrascora I'll shamelessly snack from my goodies bag if I need to because I'm at risk of going hypo. I will take a bolus correction later on if I've messed up and am going higher than I'd like.
Of course all of this has come from time since diagnosis, experience with that time and thus confidence in what I'm doing as well as confidence in knowing I can put right a poor decision while eating out. I do still pre-bolus; partly because I know if I eat while above 7 or at most 8 (actual) then my bolus calcs don't work too well - too much natural insulin resistance - and this comes back to bite me later on. So I'm happy to pre-bolus, risk drifting low, knowing I can manage that before I become hypo. Libre, even when it's not in harmony with me, is a huge bonus to my daily D management.
One thing I have always done, so far, is to tell the waiter or reception desk that I'm insulin dependent, that I will probably have simple questions about portion sizes for those menu choices that might be high carb content and that I have my own goodies bag if things go adrift. This has only once been a problem and I over-estimated the common sense of the manager/owner who went extraordinarily and unnecessarily defensive. But that was a notable exception. Generally I find restaurant and cafe staff are alert to food allergies and while they often don't know much about insulin dependency they are amenable to dialogue to assist me in making a menu choice. When a waiter or waitress is new, they can find a question about the weight of, eg, a portion of chips challenging; but I know most chefs know the answer - they need to, to stay in budget for their menu costings. So asking has never been a problem.
If my menu choice might have a thickener such as cornflour in the gravy/jus/sauce - or might not - then I'll ask if the chef knows and make a guess according to the response! I no longer am too obsessed with getting the carb count spot on; I can adjust with a bolus retrospectively if necessary.
The big thing for me is I now enjoy eating out, I no longer worry about the D aspects and just take things as they come along. But I was not like this a year ago! The only thing I've not yet done is try a "sampling menu" of many small courses that one sometimes finds at gourmet restaurants. So far that still makes me hesitant. I was intrigued to discover that, apparently, the restaurant chains run by Raymond Blanc didn't have the full nutrition content for all their menus, even though the menus are determined by the head office and designed and tested by teams of chefs before being put in front of the public at large. They know all the portion sizes and allergy foods within, but not the carb counts. I meant to email their head office and establish if this was really so, but forgot; then apathy overtook my query!
Go dining again and enjoy!