Yeap anything is possible.
First up, you will need to dig huge trenches to lay cables throughout your country, then lay the cables. Alternatively you could hire bandwidth on existing cables from an already establish provider who is also acting as a wholesaler. Costing you Millions to Billions of Euro's depending on what you want
Next you will need to build what we call POP's or Exchanges at strategic locations through out your country, probably you could house your Millions of Euros worth of equipment in existing Telecom companies point of presences, or you could build out your own.
The you will need to create your core layer of equipment, something like ATM over Fiber, or whatever you choose, with very expensive Routers and Multi-layer switches. You will then need to contract with An Internet Exchange to use an exchange, or alternatively invest millions more in starting your own one. At the internet exchange you will route traffic between your ISP and other ISPs.
You will also need to buy a block of IP address from interNIC to use around your network.
You will also need to hire 100 of engineers to set up all this for you and maintain it after.
This project of yours will involve millions of Euros (maybe even more if you want to start from scratch) of Investment, and years to complete. Not to mention years of experience to understand the requirements and more to competently implement the deliverables.
Good luck