The most difficult part of creating a programming language is probably going to be building the compiler.

You can lay out your structure and syntax first.

But the most difficult hurdle will be this:

say you have:

Dim I As Number
Target I = 0 To 50
Print "HI"
Run Target


How do you go about converting that to even a low-level language such as C?

You have to keep references, allocate memory from the stack, manage scope, and more... I mean its really going to be a waste of your life no offense.

You want to do something really cool... build a biological computer that uses living cells for memory. Then you can be the first to build a programming language for that computer. Now, that would be something useful and a learning experience.