[TheTrue]

How do and where do i find and remove the
Welcome to JGRP
Welcome to the brand new JG:RP.
Welcome back
and that stuff?

[Freaksken]

Search for those strings with ctrl + f in the script and comment them out or remove those lines.

[BrianFaria]

Search the text in the gym and linters, including the script, that is, for example, "SendClientMessage".

[Quinncell]

My guess it is on OnPlayerConnect, could be somewhere else though.
When choosing to edit a gamemode you need to be really good at finding stuff.Think logically and you will find it by yourself.

[StrikerZ]

No I have used that script. Use /motd and /vipmotd IG. Rep if helped.