[OoAMoO]

How can a textdraw be used to get vehicle speed, health and player stats?

[Drebin]

First get all the info you need and save it into a variable (Player health with GetPlayerHealth for eg.)
Then use TextDrawSetString(NameOfYourTextdraw,VariableYouWa ntToInsert)
And then TextDrawShowForPlayer(playerid, NameOfYourTextdraw);