restaurant etiquette

Just some general questions about etiquette in restaurants. I am visiting Moscow and St petersburg this fall. I've been to Russia before and noticed that some restaurants, you just seat yourself, others, you wait to be seated. What is the best way to find out which is the right etiquette? And how do we say "do we just seat ourselves?" (mozhno cidimsya?)

Also with the menu, looks like you order appetizers, main course and dessert all at once. Is that true for all restaurants or just the lower-middle budget ones?

1. Instead of guessing, you can simply ask a waiter or a barman "Здравствуйте, куда (мне/нам) можно присесть?"
Zdrastvooyte, kooda (mne/nahm) mozhno preesest?
Or can we take these seats? (can we sit here?) Можно нам здесь расположиться?

2. All at once by default (at least in every single cafe/restaurant I've ever been to) but you can easily change the sequence ny just asking the waiter to come up later (in 10 minutes, after the appetizers) and you will finish the order. I guess this is not a big deal.
- Вы не могли бы принести салаты и подойти попозже, мы закажем остальное?
- Конечно
- Спасибо!