One of the things about learning 国語 (Kokugo, the Japanese language which is learned by native Japanese) is that they have different ways of identifying their group 1, 2 and 3 verbs.
If you are unsure if a verb is group 1 or 2, remove the る、ない、た、etc from the verb and add a ない、if it ends with a [あ]-sound, then its a group 1, else its a group 2.
e.g はなさない (hana-SA-nai) : group 1
たべない (ta-BE-nai): group 2
みない (MI-nai): group 2…
Have a good weekend ahead.