Really sorry for this newbie question

, It's been forever since I've played this game and I've essentially forgotten most of the rules.
I see that some units come with a dedicated transport, for example I can put meganobs in a battlewagon as a dedicated transport, or I can put boyz in a trukk. But I see people putting their burnas in a wagon, even though the ork codex doesn't list a dedicated transport. Do you just start out with a wagon next to the burnas and have them embark the first turn?
Sorry for the newb question, thanks for all the help!