I can boldly say that you are wrong here ensuring a stable source of income before starting investing is not a basic condition of Bitcoin investment, the basic condition is having a discretionary income, no doubt that having a stable source of income is good but it shouldn't be seen a basic condition before starting bitcon investment because there are those who's income source are not stable but yet they still buy Bitcoin whenever there money comes in like a contractor.
If we look at it basically, every investor must have an income to be able to invest in anything including Bitcoin because it has become a fairly basic foundation for all investors. Regardless of whether they have a stable income or not, income must still be there to be able to start investing in Bitcoin because the basic action of investors is to buy Bitcoin with the amount of funds they have. As for how to manage it yourself, I think it is more about each individual's strategy because as long as the intention to buy Bitcoin is still in their own heart, of course it will be done very wisely without looking at more suggestions that might make them dizzy.
The point is, investing with funds that are ready to lose, regardless of the income, whether large or small, if we can manage it well, investing will be more enjoyable and of course safe. In my mindset about investing, if you want to start investing, try to use the principle that you must have a reserve fund, at least three times your income so that the money that goes into the investment is really not money for other things or idle.
That is the importance of cash management and emergency funds before investing in addition to income issues. However, even though these funds have not been collected, don't forget to start looking for information and knowledge about investing. Just take action, learn the knowledge so that when you have everything you can easily invest.