Need tutorial on adjusting volume of various tracks at different stages .

So i finally got my first song done in this rather marvellous DAW , But now i need to be able to adjust the volume on different parts throughout the mix .
Like say i have 1 - 2 - 3  tracks and i need to have pretty high volume on 2 for say 45 seconds and then it needs to be lowered for a minute and so on .
Hope i have made sense but am brand new to using DAW`s .
I want to get it all ready for being able to finally export it as a mp3 file and sharing with friends .
 
What is the process know as or can anyone point me to a tutorial .
 
Thanks 
Dan

Resonant Serpent
Automation is your friend, and essential for mixing. It will do exactly what you need it to. Lots of tutorials on youtube.
 
 
https://www.google.com/we...0tutorial%20automation
 

That`s the one , I knew what i need to do but not what the tool was called . Thanks very much
 
It will take longer to mix this track than it did to record it haha .
 
Dan