This is 100% how I felt when I first started. I felt very overwhelmed and honestly was close to not playing because it felt so unorganized.
I don't really like the "open world" system they have in S/V. I think they did a WONDER Jon on Arceus, bit this one seems so... random. Hell, the game was even saying that you could go anywhere (which you can), but you also can't due to the last of the Pokemon and gyms.
I don't get it.
The way I was able to even figure it out was with a guide on who to actually battle first and in which order lol
After I found that, I was able to enjoy the game a bit more because I felt like I was back on the road of the story.
I like the game and I still have fun, but I honestly think this is the worst one in terms of organization );
Oh! As for lving! A good way to lv is to use the Go feature. The one where you just send your pokemon out and it goes on a rampage on all the wild Pokemon near it lol
I did this and was able to get a good amount of lvs in for my team