fuck is a sign that you're pissed off by something or someone.
The other meaning of fuck is to have sex or whatever.
Also:
fuck is a very fucking cool word that everyone fucking uses with no fucking context and i always fucking use them as example of that you are reading my fucking creation and you're fucking retarded you just wasted you're fucking time to fucking read this fucking sentence you fucking idiot.
1st person: *texts* I think your car broke down
2nd person: *records* Fuck! What the fuck is fuckingly happening in this fucking place? What the fucking fuck is fuckingly happening in the fucking car? Everyfuckingwhere!
All purpose word, has many uses, and add insulting, angry, or joyous context. Also can add emphasis on the subject. Basically use it whenever the fuck you want.
Person 1: I fucking hate Fortnite Person 2: Fuck you, that game is fucking fun.
Person 1: Alright fine I’ll fucking play fortnite but only a couple of fucking games.