The most important thing is to start consistently, not the amount of Bitcoin. To start any investment, you should first have money, sufficient knowledge, or absolutely perfect market conditions.
You don't need to understand everything about Bitcoin before you invest in Bitcoin, and you don't need to start your investment in absolutely perfect market conditions because Bitcoin is highly volatile, and you don't know when the market will be favourable for you to start your Bitcoin investment. If you have a source of income that guarantees you discretionary income, you can adopt the DCA strategy and start your bitcoin investment weekly or monthly based on the one that is convenient for you,
and you need to set aside your backup funds or emergency funds. In case you have any emergency you didn't plan for, you can depend on your backup funds or emergency funds to solve your emergency, and it will not influence you to sell your bitcoin.It looks like you are confusing an emergency funds and backup funds as the same, no they are not bro, they are both instrumental to the security and growth of your Bitcoin holdings, but they didn't have the same functions.
An emergency funds is the money set aside to handle real life emergencies that threatens your Bitcoin holdings, or in other words you can say that it stands as the last layer of protection to your Bitcoin investment. You don't temper with it unless their is a real life emergency situation that threatens your Bitcoin holdings, unlike a backup funds. While a backup funds is money set's aside that can be used to service your other minor needs that is not part of your basic needs, but are very important, it can also be used to buy aggressively during the dip, so a backup fund and an emergency funds are not the same bro.