No, they don't. They're a way to try to write phonetically the way that the phrases "trying to" and "I'm going to" sound when they're spoken quickly and slurred together. For the love of all that is good in the world, do not use them; just say "trying to" or "I'm going to."

They exist and are used only in social media platforms between the younger generation (and maybe seldom in oral speech, too). The correct spelling is "imma" and you can use them both if you wish, however I would stress that you don't get too used to using them and forget the correct English, because I can almost guarantee you will be using "I am going to/I will" and "trying to" more than their slang forms!

People do dismiss them as poor English and although that is true, it is important to learn them regardless [emoji] You will encounter these words frequently, they just slip out when speaking to people from certain regions of the UK. Even I use them! Best of luck

These words are slang words and poor English...tryna="trying to" and I'ma="I am going to"