Just realized I posted this in the wrong group – I’ll ask the question in the correct one. Thanks.
Install BuddyPress first.
Activate your Evolve theme.
Install and activate BP Template Pack plugin to make your WP Evolve theme compatible with BuddyPress.
Go through the BP Compatibility Process – https://codex.buddypress.org/theme-development/wordpress-to-buddypress-theme/
Before installating BuddyPress – https://codex.buddypress.org/getting-started/before-installing/#system-server
@mercime – Thank you! My Evolve theme is already active – it’s an existing site that has been up for 6 months. Am I still OK to proceed?
Ideally, you should create a test site with the same server environment you have now along with the plugins and theme. Then install BuddyPress etc. and do the BP Compatibility process then some exploration and testing of other BP plugins.
Now, if you are adventurous, you can always back up your database and server files, then proceed with the BuddyPress installation and then the BP Template Pack plugin, etc.. If anything goes awry , you can always revert your installation to what it was before with your back ups.
The old back-up restore trick! 
Ok – that makes sense and is probably the route I’ll take. I don’t have an easy way to create a test environment without signing up for another hosting plan with my provider, hostingdude.com. Anyway – I appreciate the help, I’m off and running!
Go forth and multiply your membership
@mercime – hoping you can translate a message I am getting during the Network Setup, I want to make sure I don’t assume that’s it’s not a big deal:
“Because your install is not new, the sites in your WordPress network must use sub-domains. The main site in a sub-directory install will need to use a modified permalink structure, potentially breaking existing links.”
The part I’m confused about is the modified permalink structure portion. I’ve enabled “pretty permalinks” – i.e. “mysite.org/title-of-my-blog”. Does this mean the message won’t apply to me, or is it going to make another change to my permalink structure? Can you provide an example of what the URL will look like for other sites/blogs that I add to network?
Also, regarding the Network Title setting – how does this setting present itself downstream? Meaning, will other users see this value (URLs, etc.) or is it just a backend setting?
Many thanks!!!
Creating a network whether in subdomain or subdirectory structure won’t affect your permalinks per se. As per https://codex.wordpress.org/Create_A_Network it’s how your subsites’ URL’s will show up online. Remember, these are virtual subdomains, i.e., even with a network subdomain set up like http://subsite1.mysite.com, it will be set up in server with folder structure wp-content/blogs.dir/2/files/year-etc. unlike that of physical subdomains /subsite1.mysite.com/
Network title is the title of Main site. As for subsites in subdomain/subdirectory it will be what you title each one and the default description would be something like “Just another [title of main site] site.”
For more assistance re multisite installations, please post at the WP multisite forums https://wordpress.org/support/forum/multisite
