Really glad to see your interest in Bitcoin but if you live with your parents then you will invest in Bitcoin with their permission. Try to convince your parents well, most likely if you convince them well they will listen to you and help you enough to invest in Bitcoin. If you are self-employed and you want to invest a certain portion of your salary in Bitcoin then you can because you probably already have all the knowledge to acquire in investing in Bitcoin. But if you inform your parents and then invest in bitcoins, your parents will have no chance to blame you later.
If you really want to make your life better and you have money to invest in bitcoin and you have tried your possible best to convince your parents and refuse to understand the impact you are trying to bring in to them, and you have your own money, I don’t think it is necessary to wait for their approval before you will invest in bitcoin, since it’s your personal money and not the family money.
However, if you have the knowledge and everything you need to know about bitcoin investment, then seriously, your parents will not blame you at the end of the day because you do the right thing for yourself; moreover, not their money is yours, so even if the investment goes sideways that is not favourable, you won’t bother telling them because you already know they did not support it and you too take the risk on your own.