If a Statement, for example, is an IfStatement will it go to the 14.6 The if Statement 14.6.2 Runtime Semantics: Evaluation ?

Yes.

I'm mostly confused because there are productions that have their RS: Evaluation like IfStatement and some don't have the RS: Evaluation like Statement,Declaration, etc...

What does it mean?

This is (in recent revisions of the spec) even explained in §5.2.2 Syntax-Directed Operations. In particular,

Unless explicitly specified otherwise, all chain productions have an implicit definition for every operation that might be applied to that production's left-hand side nonterminal. The implicit definition simply reapplies the same operation with the same parameters, if any, to the chain production's sole right-hand side nonterminal and then returns the result. For example, assume that some algorithm has a step of the form: “Return the result of evaluating Block” and that there is a production:

Block : { StatementList }

but the Evaluation operation does not associate an algorithm with that production. In that case, the Evaluation operation implicitly includes an association of the form:

Runtime Semantics: Evaluation

Block : { StatementList }

1. Return the result of evaluating StatementList.

So since there are no "Runtime Semantics: Evaluation" for the Statement production, it gets implicit semantics that will simply evaluate the respective statement kind.