CC Blooms is one of the main gay venues in Edinburgh. It's a large place, and open all day for food, dinner and drinks. At night at turns into a bar and nightclub.
In the weekend it can be packed. Including many young female visitors doing a "safe night out". Fortunately in the weekend the club in the basement is open which is more gay. There is limited internet reception downstairs, which probably makes it less interesting for the girls night out with their instagrams ;-)
In the basement you can also find a coat check. The venue has security guards outside. If you look young make sure to bring ID for checks.