Best Language to Create Your own Language

Question

I tried to make my own language on C#.
I made a winform Application with richtextbox.
Added a menustrip, some tools to exexute code.
My language works like that:
it check all lines in richtextbox using foreach(string s in richtextbox1.Lines)
And after foreach line, it checks for function, like if(s.Contains("print))
If function found, a code gets a string from function,
I made my Own .dll with GetBetween(char one, char two) method.
I used that method to get a string between a double quotes in function
When code got a string from function, that string Is adds to another
richtextbox, i called it output.

I know i made a language on C# wrong.
But i dont understand how to do interpreter, etc...
I check all topics and tutorials on Google.
And its not explain where Is got a methods like
Parse,Token, from what library Is it, or Is people
MADE that methods?

Answer 1

making a language requires using lexers and parsers which will recognize language syntax and translate it into a different language (usually either C or ASM) behind the scenes when your program is executed.

for a lexer you can use the program "flex" and for a parser, the program "bison" (there are more, these are just my recommendations)