There are some issues with your approach:
\newcommand takes the number of arguments in brackets
 and then refers to the arguments as
#2. So your second code segment should be
And would be called by
so that part you got right.
Next, as David Carliste commented, defining
\Large is redundant and may result in a loop. Furthermore, you can't use
\newcommand for existing commands, but need
If you simply want test to be
\Large you can simply nest commands:
The indentation is superfluous, but I hope it clarifies the idea. The part where you renewcommand
\Large is unnecessary.