How to create code editor and compiler for multiple languages

Compilers are very difficult to create. You'll have to read Touring Machines :)

 

Editors are not that difficult. You can learn a lot from reviewing and understanding open source editors source code. For example, VS Code is an open source projects and supports several languages, means it uses compliers for those languages. 

 

Here is VS Code: 

https://github.com/microsoft/vscode 

 

Why do you want to create your own Editor when there are many good open source editors are already available? I suggest look into these open source editors. 

All code compilar's API are paid , for example you can embed the below API which suppports almost all languages

https://sphere-engine.com/compilers