If a newbie happens to enters into Bitcoin investments with what you said, honestly speaking that newbie wouldn't even last a year in his/her Bitcoin journey coz he may end up using his discretionary income for emergency situation or even channelling it to his reserve holding.
When an investor starts using funds meant for his Bitcoin investment for emergency situation,then his Bitcoin investment will be delayed. As an Investor you should know how to split your discretional income to serve a greater purpose . After taking care of your basics needs, whatever excess cash that is left is your discretional income ,parts of it should be reinvested into buying Bitcoin for the week while the rest of it should be used to build your Backup funds (Emergency & reserve fund). Your Emergency funds is buildup from your discretional income and should only be used
to counter anywhen real life Emergencies
strikes.
You cannot build 3 things at the same time. So first you have to build an emergency fund and after that you have to build it gradually. But if you delay investing to create this fund, it will never be the right decision. You will have to create the funds along with the investment.
If you have a strong weekly flow of discretional income,then you shouldn't have any difficulty investing in Bitcoin alongside building your Emergency and Reserve funds.
Building your Emergency fund doesn't require haste, it's a gradual process and it is appropriate for you to build up your emergency fund for a period of 3 - 4 months to produce a backup strong enough to protect your Bitcoin investment from any emergency crisis that may threaten it.