There is no mistake because we are here to learn and discuss about Bitcoin and cryptocurrencies.

This types of threads is frequently been posted here, but your effort to bring out something like this is as a newbie is commendable, I just hope you also learn from what you posted not just to post what you don’t know because of merits.
The methods you mentioned are good but DCA method is good and that’s what we are mostly advised to use especially if we don’t have stable source of income.