Well, your points are not actually bad but the most important knowledge that a new Bitcoin investor needs before applying security to his holdings is how to buy. If an investor knows how to buy he can also know how to secure his Bitcoin, at that moment he believes that it is his asset because he exchanged his fiat for Bitcoin through p2p, at this first point when he has purchased Bitcoin he doesn't care if he has make profits or not, the next step is for him to send the Bitcoin to the wallet he will use for holding. Which means after buying, the other important step is sending.
As a newbie to Bitcoin investment, you also need to calculate the figures of Bitcoin you have, so that while sending from the exchange you bought Bitcoin from to the wallet that you will use for holding you can be able to figure out the fees for your transactions so that you will know the figures of Bitcoin that you will receive.
Personally I feel a newbie should learn about a secure wallet and method to implement
You have said well but there is also something I want you to understand, as a newbie learning about a secured wallet when you have not yet but any Bitcoin is not a good move, the important thing is buy the Bitcoin first before any other thing, while waiting to know a good and reputable wallet to hold your Bitcoin you might have missed some good opportunities that won't come back again. Now let's say you wanted to buy $200 worth of Bitcoin, and you are still waiting because you are contemplating about a more secured wallet, you might miss the dip (if you are also the type that want to buy during dip period) and you might still end up not buying at all because you haven't seen the one that's suitable for you. Am only say that you should buy first before make any other move that's why buying is the important knowledge a new Bitcoin investor needs to know.
Before learning how to * or sell.
You are still getting it wrong, as a new Bitcoin investor you don't need to sell yet because you haven't achieved anything (unless you are not investing for long term).
Long term investment is the goal and a new Bitcoin investor who has applied DCA method should not think of selling his/her Bitcoin anytime soon because holding BTC for long term is not about sell and buying again (only traders does that), you only need to buy, buy and buy until 5 or 10 years of investment. Dipping your hands into your investment won't profit you anything rather it will make you not achieve a good portfolio.