Hi Aditi,
Interesting question.
There are a few ways to think about this.
Firstly, if the company is offering this benefit, it means they want their employees to have a good work life balance, and be at their very best when they are at work rather than worrying about personal issues that need time to solve.
So, take the time you need. That should be your guiding principle. Neither be defensive about it, nor misuse the trust that is being placed in you. Go with your genuine needs – and needing a “well earned” break is also genuine!
If you really need a mathematical answer, then refer to the state government rules about holidays where you work. Typically, Indian States expect employers to give 10 festival holidays ( your company may be publishing a list), plus 20-25 days as leaves under different headings like casual/ sick/ annual/ earned leave. So four to five weeks ( including weekends) is a fair rule of thumb for holidays per year.
I would additionally state that give enough notice for long breaks and support the team to cope with your work load while you are away. Except for sick or emergency leaves, it is never good form to not turn up.
And finally, obviously, it always helps to talk to a cross section of colleagues to figure out the culture when you join a new organization. So talk to your HR, your teammates/ peers. That should give you a sense of what is acceptable.
I am a big fan of talking to your manager very clearly about expectations – both ways- not just about off days but about all kinds of rules of engagement- so that you are working with clarity and neither of you have to operate on assumptions.
Hope these are helpful.
Take care.

Hi Aditi. My husband works for a company with similar policy. The first year they introduced the policy, they actually witnessed a dramatic drop in employees taking vacations! After which HR mandated leaders to ensure team members take time off, adding it in leadership performance goals.
I agree , being new & with WFH , it will be difficult to figure the ‘ unsaid’ norm. Aside from the obvious asking your colleagues, holiday auto answers is a good way to figure the average time people take off.