The problem is in the case of overloading or lambdas being "hairy", it follows you're well outside the scope of a beginner. Generics are explicitly outside the scope of a beginner learning to implement a basic type system.

In the case you're not a beginner, it's not true that no literature exists on type systems and their implementation. The mountain of literature is essentially inexhaustible, but if you're still wondering about how to implement any type system at all, if you've never done it before, you really need to not worry so much about that. Kind of like how you don't even think about implementing a tracing jitter before you've written the world's shittiest tree-walking interpreter.