Hey I'm not sure if this response is too late but...

In Digital Ocean:

1. Log into your DigitalOcean account and click on the project your working on.
2. After that click on the domain you'd like to edit (EX: yoursite.com)
3. Once you click you will see something that says hostname in the space enter: www
4. Next to the hostname space you'll see something that says "will direct to" click that space and select your droplet
5. After that click Create Record

In Wordpress:

1. Log in to your site admin
2. Go to your settings
3. In the sections Wordpress Address and Site Address change the url from https://yoursite.com to https://www.yoursite.com

Sorry I couldn't answer the SSL part, I am still figuring that out myself.