What is gambling?
It is the wagering of money or something of value (referred to as "the stakes") on an event with an uncertain outcome with the primary intent of winning money or material goods.
Where to gamble?
There a lot of sites where you can gamble i will name some of them for example:
There is a lot of sites where you can bet i will put links where you can find almost all of them, there is the link:
https://www.csgoreferrals.club/
or
https://www.csgowinner.com/toplist/roulette
How to start?
First of all you will need to deposit some skins the site. There is always lowest deposit price of one skin, the most common would be 0,5€ or there is always a refferal system on the site, when you can enter a code and get some money to play for free, at the most sites you can't withdraw skins you have won for free, but there is some exception at some sites.
Is it profitable?
Yes if you're lucky but if you're not lucky or not feeling lucky dont try to play, because sometimes strange or just unlucky things happens and then you are going to lose, my self i have made some profit on gambles sites, but in the end i still lost everything just because i wanted to gamble so stop whenever you make good profit.