Hi Deepali Ahirrao,
You can only create SFDC campaigns from a Marketo program. Click on "Salesforce campaign sync" on the summary view of the program. If your CRM is another CRM, this will not be possible. And on salesforce, what you will be able to do will be limited. A few ideas to vote for :
You cannot create an opportunity from Marketo UI per se, but you can use the "Convert Lead" flow step in a campaign.
Marketo Opportunties can be created using our API Marketo REST APIs: Opportunity Objects » Marketo Developers if you don't have a CRM. Salesforce and Dynamics Opportunties must be created and managed in the CRM. There is no UI ability to do this in Marketo.