If you like to eat as much as me, your favorite phrase in Tongan will be kaike mate. It means eat to die and it's a common phrase in Tongan that you say when you're at a feast or a really big meal, just kind of joking around like, oh keep eating till you die. The Tongan people are really funny and they like to make jokes like that.
Grammatically, the Tongan language is very simple. You don't conjugate anything. There's none of the kind of gender stuff you see with a lot of the Latin-based languages. It has its quirks for sure, but it's a lot easier to pick up than other languages. It'll give you a hard time learning to, you know, to be able to joke around with people and relate to them on a more personal level because the resources aren't really there for language learning as they are with other languages.
We used to just get as many like the boys or just anybody to try to talk to me as much as possible. And when as I would start to talk with them it helped my language to progress. So number one tip for learning the language is just speak it as much as you can and you'll be fine.