Nothing good can be achieved without holding in the long term. If you do something in the short term, it becomes trading. If you do something in the short term, you cannot gain much from it. If I have done these or am still doing some things, from my own analysis, I can see that if you do something in the short term, you cannot expect anything good from it. However, some profits can be achieved but not much can be expected.
If you can maintain DCA and invest in the long term with understanding, then it is best. It is true that to get something good, you must have the mentality of holding for a long time.
I agree with DCA. But don't discredit the traders that are able to make sums of money. There's also good things comes in there.
But it just so happen that the majority who trades get rekt and that's a fact but don't forget that those traders that makes a lot of money, gets to the top as well. I'm a long term holder and I know that in fact that DCAing and long term holding is very effective. However, if see someone who makes a lot from short term trading and strategies, you cannot invalidate that strategy works for them but not for us.
The OP is someone that's new in Cryptocurrency and for a start, he's noted the best Cryptocurrency to invest on an is seeking guidelines on how to go about it, I don't think it would be right to start directing him towards the path of trading due to the high risk that comes with it, trading shouldn't even be part of his since it has nothing relating with Bitcoin investment, trading is for people that lacks patient of holding for long-term and are willing to risk it.
Whereas Bitcoin investment is less riskier and with the DCA method and the amount he intended investing monthly I believe he's never too late to start investing and holding for long-term and the good part of it is that it offers features that would help him gain even when price drops so far he's constantly adding to his portfolio for as long as he wants to hodl, probably 4- 10 years and more.