You mean regarding the BTC fork?
I am not sure how Coinbase will prepare for it but you can start by taking your BTC off the exchanges to store it into proper wallets. Have a look at this article:
Hi @shameonyoubane, sorry for replying so late.
https://bitcoinmagazine.com/articles/bitcoin-beginners-guide-surviving-bip-148-uasf/
Feel free to follow if you like the content :)