I am curious to know the number of edits I have made to questions, answers and comments of all time on Ask Ubuntu, where do I get this?
Go to your profile and click the Activity tab. Under that, click the Revisions tab. Those are your edits. Above them (and on the left) it says the total number you've made on the site.
This does not include edits made to comments, nor does it include suggested edits that were rejected (though you can look at all your suggested edits--accepted and rejected--in the Suggestions tab).
I believe edits to comments are not tracked by the system--or, if they are, that they are accessible only to Stack Exchange developers/employees. We don't have access to comment editing histories or deleted comments, so it seems unlikely that comment edits are tracked the way edits on questions, answers, and tag wikis are.
By the way, there is other user-editable content on Ask Ubuntu, too. Leaving out stuff you have to be a moderator to edit--like the FAQ: You can edit chat messages. While arguably that's not really on Ask Ubuntu (since chat.stackexchange.com is a separate site), it's directly tied to AU, so I should mention that it is also not included. You can also edit your profile (which definitely constitutes AU content), and the number of edits there is not tracked either.
As I write this, you currently have 76 edits (this is the total for questions, answers, and tag wikis).
I couldn't find it in the profile section, so to the Stack Exchange Data Explorer! Enter your userid (in your case 72576) and run the query.