How to integrate marketo with google analytics to begin with. Any material which helps in doing it?
You will find this helpful https://docs.marketo.com/display/public/DOCS/Add+Google+AdWords+as+a+LaunchPoint+Service
In general, all you need to do with GA is add the GA code to your Marketo Page Templates. You can also use GTM and disable the munchkin code if you added the munchkin code to GTM.
If you want to add Goals and Form conversion tracking, you can do this easily following the standard process in GA.
If you wanted to go deeper with GA, you can check developers.marketo.com or the GA docs.