How often to change litter

I adopted my first cat a few months ago and was told by the shelter and several people with cats that changing the litter weekly was great.

I've been changing the entire litter (wood pellets) every week and giving the box a deep clean before putting new litter in.

I scoop wee and poos each day and put another scoop of fresh litter after each poo.

However, another friend of mine (a long-time cat owner) said litter should be completely changed minimum twice a week, better three times a week.

I get anxious about these things being a first-time cat owner and I now feel stressed I'm leaving my cat to go to the toilet in a dirty environment. Any advice?

PS: I only have one cat and she's completely an indoor cat.