Just turn the warnings off in the Preferences | Warnings.
However, I would caution against changing the defaults. Most new user errors are due redefining built-in and othe variables and functions.
Redefinitions also run the risk of confusing future users, including yourself, into thinking that a particular variable or function is something different from the redefinition, because they missed the actual redefinition. It's a bad slippery slope.
TTFN
FAQ731-376