Saving patterns

[felipe46n2]

Hello, still learning this new software and really enjoying it for the most part. I was wondering if anyone knows how to create new patterns within the working session and keep the drum sounds unique to each pattern??

I spent some quality time making ten different tracks and then when I put them into song realized that the drums had all changed to the current template.

I was also curious as how to undo synth parts if u record them?
And while we r here,, does anyone know if it's possible to mix different sessions into 1 song?

Thank you for any help u can give!