Does a blogger need to pay taxes?

Good day, guys! I have a passion for blogging and planning to set up a website with an original domain name, if I start to attract readership and decided to place google adsense and generate income from the traffic, is my blog/website now considered a legal business? Do I have to register it and get business permits and pay taxes? (also, I am planning to do the website while keeping my full time job.)

1) If yes, but since it will be just a new website and it will take months to earn even a penny, can it still be recognized as blogging as a hobby and postpone the registration permits/taxes during its development phase while it has no legit income even if under an original domain name?

(and last, my sister is planning to make films and make money from views on youtube, does she fall under the same requirements as well?)

Thank you. I hope I can get a helpful answer.

I don't know if there is any exception making no need to do anything,
but if not you can check if you fullfil the demands to be a BMBE business. (Barangay/Municipaly office handle such, so they can inform you about the details. There are some small local differences.)
BMBE is much cheaper, faster and easier to register,
and NO INCOME TAX for the owner,
but other taxes are same,
and tax forms and such need to be done.