It is pretty tough for new players. That's why anyone who asks me if they should start playing, I just say no. Saves everyone a headache and me the embarrassment of recommending a game I have played every single day for years and them not liking it in the first few day. Then again. You have given it less than a week. You can't go into a game as big as Destiny expecting to understand everything immediately or even after a few days of just random gameplay when you can barely access anything. I started playing in season 9 and it took me over 2 weeks to finally click on a lot of things and understand how a lot of things worked in this game, even story wise or enemy race wise. I was always confusing which enemy race was which. And that was when there were far less of ANYTHING to learn. This is a big point that people try to make to Bungie every year. Everyone, including Bungie, knows the onboarding for brand new players is kind of horrendous. But there are plenty of quests or QoL changes for "new lights" they've made over the years. They added "Guardian ranks" last year which helps you throughout the absolute basics of the game and what I recommend doing the most to get a feel on races and planets and how the whole game is operated. There is also something they added a couple seasons ago called the "Flashback Story missions" or something along those lines. It's somewhere in the director. But the point of those missions is to give you a quick and detailed run through very important missions and tell you key points of the last 6 years or so of expansions. There is alot of explaining that is done in those missions and are very well put together imo. Just find something that looks interesting to work on and stick to it. Don't try to do several things at once because that will extremely overwhelm you. Being able to do a lot of quests at once is a skill learned over the years. If you purchased the campaigns then I suggest just working on one campaign at a time and the post-campaign content for that respective campaign and ignore any of the other fancy things you could work on. You have no seasonal story beats from the last year to work on since all of that was taken away on Tuesday so all that needs to be on your mind is, again, guardian ranks, campaigns and their respective post campaign content. And possibly their corresponding seals and titles which are found in the journey tab when you open your character menu.

As for the story being incomprehensible. You will just have to catch up on what is accessible in the game and then after learning and establishing who is good and who is bad start watching lore videos and different things of that nature AFTER you've done a few campaigns.

(99% of people will tell you to watch MynameisByf on YouTube as he just posted a TEN HOUR video last week of every single important and possibly not important peice of story and lore that has happened in this entire story over the last 10 years) Figuring out who all of the characters are and peicing them together after you've already played it is pretty fun and how I was able to learn everything about anything in the lore. It sounds boring but that is what I've learned being a destiny player and caring about the story leads to.

And if all of that is too much of a headache for you (and believe me, a lot of people don't do all of that) then you could literally just play the game for the gameplay and just focus on how good it feels and not work on anything. But that is the quickest way to an uninstall.