Hi Kimmi
The best currency to use is Egyptian Pounds - referred to as LE.
People take a few £100 of sterling and change it up there when needed or draw LE direct from an ATM using their bank card. Although in view of the problems out there at this time it might be worth changing £100 into LE at Thomas Cook/Post Office so that you have a little bit of money to tide you over, incase the ATM's are running low. You will probably not need much cash as you are AI.
Don't leave a lot of money loose in your room, get a safe.
You can book trips through your rep or book with one of the companys in Namma Bay. The later will be cheaper, but as it's your first time you might feel more comfortable booking through a rep.
If you are with First Choice, Thomas Cook etc go to the welcome meeting to get the details on Star Gazing, Quads, Snorkelling trips, you dont need to book at the meeting you can find a rep once you have decided what you want to do or compare their prices to local prices. If you go in the sea don't tread on the coral as it kills it, the fish are beautiful so it's worth the effort to snorkel.
If staying in Sharm you dont need a visa, when they try and get you to buy one at the airport say you are 'Sinai Only' and hopefully they will put a rubber stamp on that says that.
Only drink bottled water & dont have ice in your drinks. Make sure any food from a buffet is good & hot. If either of you get a jippy tummy, ask to see the Hotel Dr. & they will give you something that will clear it up in 24/48 hours or if it's not too severe go to a chemist tell them what's wrong and they will give you something, they all speak English.
Make sure you have travel insurance to cover any med costs as the Dr's can be expensive & you may need to pay upfront and claim back.
Keep hydrated with water, 7 up, coke etc. Use high factor sunscreen & take it with you as its dear there.
Not sure where Namma Heights is? If it's near Namma Bay,this is the main hub of activity with all the shops, bars, restaurants and shisha cafes, you have all the International Restaurants such as Hard Rock Cafe, Pizza Hut, Maccy D's, KFC, Chinese Restaurants plus all the Egyptian one as well.
International Branded drinks are very expensive & so is quality wine, drink local stuff you can normally get it down if you swamp it in coke, lemonade. If you have to have Barcardi, Smirnoff etc buy a bottle on the plane and have a drink on your balcony. Local beer is fine and not dear.
You will get friendly hassle here, especially if you show any interest in goods in shops. Most things aren't priced and you need to haggle. Offer half of the price they are suggesting as your starting point. Don't buy if you think its too dear, there will be another shop selling the same straight after.
Only tip if you receive good service, don't tip if someone just does something that would be common courtesy here, like holding a door open for you. There is a tendancy to feel you should tip for every little thing which isn't really the best way to go.
It's all just common sense stuff really and much the same as going anywhere abroad.
Hope you both have a lovely time.
Doe