"hajimemashite" but after you can add "please look after me in the future" or something like that (not really sure of the translation but basically it means something like that~) : "douzo yoroshiku onegaishimasu" for example you'd say "hajimemashite, watashi ha <ichigo> desu; douzo yoroshiku onegaishimasu" if you wanna be really polite ^^