Overall you give good advice, the only thing I would add is that DCA is also good for people who don't have a big income and therefore can only invest what they save from their paycheck. For most salaried people. I am not a newbie and I do it.
Note that one can never increase his bitcoin investment portfolio through trading but rather you will decrease or loss your bitcoin through trading, because trading isn't something very easy as people thinks it is. HODLing is the only way out.
Well, it's not exactly like that. Yes, there is a small percentage of people who make money from trading, but it requires a lot of dedication, study and effort. It is much easier and safer to buy and hold Bitcoin in the long run.
You need to have a means of income to enable you buy bitcoin, and if your income is very low, try to get a second means of income, if you really believe in bitcoin. No amount is too small to invest with, the earlier the better as time waits for no one.
Good advice.