I want to start gambling
Give me suggestions, such as which casinos are trustworthy and worth trying.
There are many trustworthy casinos existing nowadays. Just exert an effort to do a research to find out what's best for you. I personally play on the casino in my signature, in Roobet and Livecasino. Just don't forget to read the ToS to avoid breaking the rules. Moreover, before start playing be aware of the consequences in using your money to gamble. Because winning is not easy.
Which games are suitable for beginners?
It depends on what you like since we have our own preference. When I was a beginner, I enjoy playing dice.