Just imagine that an investor start investing which money meant for his basic needs or he invest without putting and emergency and reserve funds in place , just in case of emergencies, he is doom to fail, so a good management skills is highly needed if an investor want to be successful in his investment.
Emergency funds should be used for a real life emergency and that should be set up, immediately you have started your bitcoin investment, if you do not have anyone available before you decide to start investing into bitcoin. You don't need to put them in place before you start your bitcoin investment because it will waste your time from getting started early and start building your bitcoin portfolio.
You can share your discretionary income into two part and use one part to DCA weekly overtime and use the other part to build your emergency funds of at least three months of your income. When that's done, you can channel the money for building your emergency funds into building a reserve funds. It can take up to one year or more to build these backup funds and that's the reason why if you don't have it available already, you don't need to be waiting to build them before starting your bitcoin investment.
If your goals are long-term, there's no harm in delaying establishing an emergency fund. You can build it over time when you're ready to divide your discretionary income between investments and an emergency fund by increasing your income or through other means to increase your discretionary income and support your ability to set aside funds for investments and an emergency fund that you can consistently use.
If your discretionary income is only enough to buy Bitcoin, do so. Don't wait until you have both to start investing, as that's a waste of time. Time is of the essence when it comes to accumulating more Bitcoin and holding it for the long term. Long-term goals are broad, and long-term investment goals will help you address any gaps or needs and also increase your knowledge, which you can gain over time, slowly but surely.