YOU SAID:

this is my first time doing this

INTO JAPANESE

これをするのは初めてです

BACK INTO ENGLISH

It's my first time doing this

INTO JAPANESE

こんなことをするのは初めてです

BACK INTO ENGLISH

It's my first time doing something like this

INTO JAPANESE

このようなことをするのは初めてです

BACK INTO ENGLISH

It's my first time doing something like this