There should be a folder called Scoring (at least when you first open marketo). You can create a Program called "Scoring" and create campaigns that listen for particular behaviors like Clicks Link In Email > Score +4
Go to Marketing Activities and create a Folder called Scoring. Then a programme with two types of campaigns: Behavioural and Demographic. This will affect all your emails/campaigns/forms except if you decide to create a specific points attribution to a specific Asset.
You should also probably start thinking about a Revenue Cycle Model which will be the next step from your Lead Scoring implementation in your Lead generation strategy.