How to get to Gaea Town HELP

Hey I just got out of the dream realm after receiving my 8th badge and was told to go to gaea town next but it seems the only way there is with rock climb and i never got it so is it a tm/hm or do i need to find a pokemon with it or is there a key item for it because im really lost right now any help is really appreciated

Rock climb requires you to beat the elite 4, which you should do right now.

Okay thank you so much i just figured because Nora called and said you should meet her there asap thats what i needed to do. its a little unclear lol