Google Analytics Questions?

Need to figure out how to setup my Google Analytics account for my website and need some good advice. (My site is not online yet.)

1. If I pick a plugin, I will be able to track all my data just like with my google analytics account?

2. Will I be able to track all my data within my WordPress dashboard and my google
analytics account with a plugin?

3. If I decided to put the code into the webpages, where do I add the code and make sure it’s working right?

4. Would it be better to get my site online 1st and then add Google Analytics to it?

5. Or setup the Google Analytics account 1st and then enter it into the site?

Appreciate anyone’s input.