I personally would suggest you to learn about wallets first. Because if you don't understand this, I think it will be a problem. Because a wallet is where you store the bitcoins you have. So don't store the bitcoins you buy on the exchange, because it is very risky. That's why I suggest you learn about wallets first. Then if you already understand about wallets, then you can buy bitcoins on the exchange and send them to your wallet. Also, don't forget to be more careful when you are going to send your bitcoins to your wallet. Because if you make a mistake with just one letter when you enter your wallet address, of course it will result in your bitcoins being lost. That's why when sending bitcoins to the wallet you have to be more careful.
Everything you mentioned are fine but to start investing in Bitcoin, you don't need to know about the wallet first, how many people can understand this first? If you are experienced, the best advice may be to initially present the basic knowledge correctly to inexperienced investors, because through this they will be able to understand Bitcoin investment easily. So I personally think that knowing the wallet from the beginning is not subject to basic knowledge.
When a new investor starts investing then he will be able to select the right wallet when he gradually become experienced. Moreover, since we are discussing DCA here, perhaps by investing through this method, one can gradually learn more and master many things related to investing.