First post, Quick Question

Hey everyone! This is my first post on here so I apologize if it’s in the wrong place.

I am getting back into game development after a 10-year break! So as you can imagine my knowledge has regressed however I know that technology has improved.
My question is somewhat simple but my concept for a project would rely on this core mechanic and I wanted to get an idea of how plausible it is.

Here is my question.

Step 1(Offline) In my project, I would like to have the player manage a base similar to games like “The Last Stand - Dead Zone” (A simple overview of your base where you can place buildings and manage the production of resources, defense etc)

**Step 2: **Once a map icon is selected a view of the surrounding area pops up and the player can select a location (Factory, Grocery Store etc…)

Step 3: (Online) Once selected it will load a map and the gameplay transitions into a first person shooter with a map size similar to most smaller scale shooter games. (Not a massive area just a couple buildings) Where there is a chance that another player can join as well.

I hope that you can understand what I mean. I know I have a lot of research ahead of me but I just wanted to see if this concept was plausible for a small developer. Thank you