Fighting has been ordained for you, though it is hard for you. But it may be that a thing is hard upon you though it is (really) good for you, and it may be that you love a thing while it is bad for you. Allah knows (all things) while you do not know. Q2:216
1.Fight with your own soul by abstaining from what Allah and His Messenger has prohibited for you.
2.Fight with the greatest enemy [Shytan]
3.Fight in the cause of Allah [ self-defense, by defending your lands and by not allowing to be/get oppressed].