Trading strategies vary according to what you want in the short, medium and long term, in any case as long as your strategy is only to buy, DCA works.
i don't think he is a trader. for someone who writes just those sentences, you can already tell all he wants to do is hold.
withdrawing your coin from coinbase as well will be a good idea. you don't wanna wait for them to ask for your SS ID as part of KYC, while they still are not doing that, withdraw your coin after buying. buying just BTC and keeping it in a wallet is often the strategy of every investor.