No, this is not the normal number of tiles.
It's too much and most likely Unity just won't be able to handle that many files.
Also it will give you an application size of tens or hundreds of gigabytes, which is too much.

Overall you are on the right way.
But you need to think about how to reduce the number of tiles and the size of the application.
For example, reduce the maximum zoom of downloaded tiles.
And/or combine a block of tiles into a large image (a 4x4 block of tiles can be combined into one 1024x1024 image, 8x8 - 2048x2048, 16x16 - 4096). One large image will greatly reduce the number of tiles and this will have a size much smaller than the sum of the sizes of the tiles.
And/or you can split the tiles into AssetBundles.

I'm new to coding and especially to this plugin. I'm trying to run an offline map focused on a specific area and I'm curious about the proper workflow. I would appreciate some guidance or feedback to confirm if I'm on the right track.

Here's my process:

    I'm thinking of using either a "limit component" or a "lock position component" on the map to specify the desired area (although this might just be for convenience and not strictly necessary).
    Next, I plan to use tiledownload.cs to download the tiles for the designated area.
    Once downloaded, I'll move these tiles into the resources folder. Afterwards, when creating a map, I'll select the "resources only" style.

However, a concern I have is regarding the tile count. If I aim to cover a larger area, I quickly end up needing to download over a million tiles. Is this a normal constraint, or am I missing something?

Thank you for your assistance,
Daniel