i agree with wonderkid. The arrangement depends on the song. A lot of times u just know what to do regardless of the ´rules ´. But another method is to track out as you play and make the beat. Like when u have you drumloop ready, just loop for like 100 bars. And then u can add the main melody and start recording all the other stuff at the right positions. Like if know im going to have another isntr come in at 8 bars ill just record it 8 bars into the verse so that it will be arranged when i press stop.

If youre looking for like a songwriting/beats arrangement a general rule of a pop/rnb sequence would look like this: ( this is a starting-point of course )

Intro: 4/8 bars
Verse: 8 bars
Pre-chorus: 4 bars
Chorus: 8 bars
Post-Chorus: 4 bars ( usually this is sort of an instrumental part with just the beat going and the vocalist just gets ready for the next verse )
Verse: 8 bars
Pre-Chorus: 4 bars
Chorus: 8 bars
Post-Chorus: 4 bars ( To make smoother transition the post-hook is often placed here as well, but feel free to go straight to the bridge )
Bridge / Break: 8 bars
Chorus: 8 bars
Outro: .....

Some songs even have something that might sound like a 16 bar chorus with diff instruments and vocal parts separating two 8 bar sequences...