Welcome!
Here's my view:
Breakfast - 4xeggs scrambled with lots of butter, whole avocado, a couple of slices of smoked salmon (delicious!) This kept me filled up until around 2.30pm. Normally I'd be hanging out for lunch at around 11am.
Whilst this sounds lovely, it's a lot of food! Although I tell people not to count calories on Bootcamp, it's also not carte blanche to over-eat, and I worry that this is far too big a portion.
Lunch - salad with tinned tuna, raw cauliflower (which I love)
Sounds lovely! I hope you also had an oily dressing on the salad/cauliflower, and/or full fat mayo? Remember, it's the fat level that we're aiming to keep high.
Dinner - pork chop (with fat, again which I love, celeriac mash with lots of butter, steamed spinach in cream.
Sounds lovely, and perfect LC food, also perfect for Bootcamp.
I drank 2.5l water and it was a revelation that it didn't actually make me want to wee much more than usual - and certainly no more than menopausal overnight seeing.
Good 
Don't know how much you weigh, but if you check the spreadsheet for Bootcamp rules, and look at rule 6, this will show you how much you should be aiming for per day
Breakfast: two eggs fried in butter with half avocado, coffee with double cream
Sounds like a better portion size.
Lunch: Total Greek yoghurt - didn't feel like anything more as was quite full from breakfast.
I love Total! Hope it was full fat?
So what I'd advise based on what you've posted so far:
- keep an eye on your portion sizes, but also make sure that you keep the fat content up. It's the fat that will satisfy your hunger more than the size of your portions
- make sure you're drinking enough water
- be aware that for some people, dairy can stall them; so keep an eye on how much cream/yoghurt/cheese you're eating
But good luck! You've got off to a good start 