How your PhD will be structured is highly dependent on which county you're in. From the way you've described your degree, I'm assuming you're from North America? On top of that, there will be a few ideosynchraties depending on whether you're in Canada or the USA too.
No matter where you live, you will be making poverty wages for the duration of your PhD. Depending on the country and the university, your institution may provide you with some relief, either in the form of offering you access to student housing (which can potentially be cheaper) subsidising medical costs, if you're in a country requiring health insurance, or waving property taxes if you're staying in a rental property.
However, the assistance won't be palpable when you're struggling to stay afloat. Even in European countries, the stipends don't go very high- sure you won't be paying income tax, but you're still going to be in the bottom of the barrel in terms of wages- and you will likely be working yourself to the bone while others your age have a stringent, agreed upon employment schedule.
I've heard that if you're in the USA or Canada, your PhD can last up to 6 years. That's completely insane, to expect one to combat rising costs and inflations on meager breadcrumbs of a salary. However, if you're in Europe, expect your PhD to take around 3 years or so. I'm not sure about Asian countries, but I assume they also have hard limits on funding and how long you will be expected to research for your thesis.
To get accepted into a program, you also need to have significant research experience, and I'm not sure if universities in North America provide you with that. It seems most people had to volunteer to obtain the experience that would please admissions committees, when I've read stories of PhD candidates who study in those countries. Here, we have to do a research dissertation to graduate, so you've already gotten a taste for what is expected in postgrad.
Academia is very cutthroat and competitive. You will probably be forced to travel often and come across some poncey characters who you may or may not get along with. There is little room for failure, as a constant, overbearing presence hangs above you, threatening to lurch down and seize your livelihood and throttle your career at any moment if you don't tailor your research to what a journal fancies.
It can cost upwards of 3000 pounds just to submit an article to a journal for review, and there's a good chance that it will be immediately rejected if the journal has a high "impact factor." Such a lifestyle breeds stress and creates animosity when you can't live up to a idealised, ornate image that's been imposed upon you by supervisors.
I am not sure if this is the case in humanities, but from how it's been described to me by my professors in STEM (mainly medical researchers) the academic sector is a fucking jungle.