Security is very important, and how much or how to accumulate should not be complicated, always use yourself as the main subject you know what you can sustain a living with and what you can save up, so work with your income and as time goes you should grow.
This is actually the core point before one should go into bitcoin accumulation, the security of ones funds and this is done by the way you treat your wallet seeds phrases or keys. The key thing is setting this wallet up by yourself and not trusting third parties to do it for you even if it is some you trust. For someone going into a long term hodling the best thing should be the user of offline wallets like hardware wallets. Although it is a bit complicated but a multi sig wallet is one of the most secured with at least two co-signers, but this should be done on different to avoid a single point of failure associated with the use of master seed.
While considering the amount to invest, one should set out just an amount considerably you can lose. My take of at least 20% of your income is wise but one can go higher if they have the funds