It sounds like a big project. When I started programming, I wanted to make open world games where you could do anything you want, like most people who get started making games. I made lots of cool stuff, but nothing that was ever finished and polished despite putting years of work everyday, into certain projects.
I recommend thinking about time/money as a budgeted and limited resource. Now, making this game is not necessarily a bad thing... but every aspect of the project will take a significant amount of time, and probably 4x the amount predicted because of the many unkown challenges that always come up, 10x if you are new to programming.
Everything that's done at the design stage will save you a huge amount of time. So I recommend widdling the concept down to it's core components, so that you can figure out the bare minimum essential things so that you can have a polished working game.
Also I recommend coming up with a full list of required art assets for this bare minimum build, completely before you start coding, to include all meshes, animations, textures (to include all gui and menu textures), sound effects, and music. I know this sounds like a lot of work upfront, but it will save you a huge amount of work in the end.
When it comes to art assets, I recommend considering purchasing assets, for example this 3D set for a mid-evil village:
https://www.turbosquid.com/3d-models/max-medieval-town/1121454
Also, for cohesion, I know you said 'modern' look implying realism, but everything has a style. So I recommend coming up with a well defined art style before you start building the project as well. This will save time for your asset selection and creation.
This would include (for example): [this could be copied from the Daggerfall, but explicitly defining it will help]
General Saturation Ranges
General shinyness level of objects
Typical color palettes for various areas
Texture detail level
How pronounced small details are in models (Does the world feel more like many small details, or bigger structures... and specifically where in this range does it fall... visual examples may help when defining this)
General Mood/Feelings of objects/animations/music
* Character and Monster general Bodyshapes (what do they all have in common)
Very few things will perfectly match your art style that you purchase, but you can edit them to close the gap. Having a specific art style helps provide much more cohesion to the games look and feel.
Anyways good luck! Exciting.