No problem, happy to help!
I found what I think is a great explanation that goes to your follow-up question - take a look at this post, specifically the accepted solution -
I'll call out the relevant section here as well - "By placing it in to the Company'g Gallery, it is made available to anyone who has access to the gallery. It will show up on the home page and can be accessed from there. There is no permissioning behind it beyond whomever has access to the gallery. Those public workflows can be placed into Districts which are pretty much like folders for organizing workflows. This is done through tagging of the workflows. So any workflows that are in a District, are publicly available workflows but Districts can help with organization when you have a lot of workflows in your gallery."
What this comes down to - if you would like to utilize Districts as an organization mechanism, you can do that, but all of those will be publicly available workflows. If you would rather focus on securing content, then Collections is the direction you should pursue.
If this solves your issue, please consider marking this as Complete so others can find this as well.