I had to create a compiler for class in college.

The basics of going about doing this is not as complicated as you'd think. The first step is to create your grammar. Think of the English language's grammar. In the same way you can parse a sentence if it has a subject and predicate. For more on that read about Context Free Grammars.

Once you have the grammar down (the rules of your language), writing a compiler is as simple as just following those rules. Compilers usually translate into the machine code, but unless you want to learn x86, I suggest you maybe look at MIPS or making your own Virtual Machine.

Compilers typically have two parts, a scanner and a parser. Basically, the scanner reads in the code and separates it out into tokens. The parser looks at the structure of those tokens. Then the compiler goes through and follows some rather simple rules to convert it to whatever code you need it to be in (assembly, intermediate code like bytecode, etc.). If you break it down into smaller and smaller pieces, this eventually isn't daunting at all.

Good luck!