The command /rp automatically puts on the texturepack, for this 1.12.2 is the best version. If you are on 1.13+ then you can download this link for the texturepack: http://cdn.grandtheftmc.net/GTM-2.5.1-1.13.zip
If you are on 1.14 you can use the link, as that’s for versions 1.13 and higher. Download the texture pack here http://cdn.grandtheftmc.net/GTM-2.5.1-1.13.zip
No problem, if you need anything else just message me or another staff and we will help you as quick as we can!