There are two sorts of habits that you may develop if you teach yourself in isolation from other players:
1) Fundamental bad habits that may limit your playing.
2) Learning different variants of tunes, or tunes in different keys, which will make it difficult for you to join in with other local musicians. Folk music, in particular, is like a local dialect, where every group or session has its little ways of doing things.
In Ireland, there must be a wealth of teachers and of other players who are willing to share their knowledge with you.
There are three basic ways of playing the Anglo:
1) Just along the rows, treating the instrument as if it's two harmonicas strapped together. Sometimes this is done in parallel octaves for additional volume and punch. This is easy at first but will limit you, especially if you want to play Irish traditional music.
2) Across the rows in the main keys (C major, G major on a C/G box) and the closely related minors and modes, but with a chord/bass accompaniment. This is common in English folk music and some other styles.
3) Across the rows, using the accidentals so that you can play melody only (with occasional accompaniment) but further round the cycle of fifths: D or A on a C/G box, for example. This is a very different technique from (2) above, and is what tends to happen with Irish music.
It would be worth your while getting a few lessons (not necessarily formal lessons, but an hour or two with an experienced player) so they can show you the basics of the style you're likely to be playing in.
(2) and (3) above are so different that lots of us can do one well and can barely do the other. There is no reason you can't learn both styles, of course.
Some specific habits to develop:
1) Take your finger off the button and put it back on if you play two or more consecutive notes on the same button, regardless of whether they are in the same bellows direction or not. It gives a crisper sound with more attack.
2) Learn to use the air button in time with the music. It is a bad habit to cheat by adjusting the volume or holding down more buttons just to manage the bellows. Correct use of the air button is a vital skill, and one of the trickiest to learn.
3) Practise a lot. A few minutes at a time, every day.
4) Enjoy it. There will always be someone better than you and someone worse. It's not a competition or a difficult assignment, or a chore. Play because you love it