Because of a cast listing featuring some extras for TLT we now know that the planet where Thor and the GOTG are at is indeed Indigarr and not Centauri IV as theorized by some. The casting list features a character called “Indigarrian Cave Dweller”.
Thor: Love and Thunder | Credits | Marvel Cinematic Universe Wiki | Fandom
Indigarr is a planet from the Thor/Gorr run in the comics.
So we can deduct that the story begins with Thor and the GOTG heading to Indigarr, him going on his self discovery and peaceful journey, then eventually realize that he really needs to aid the population of Indigarr, it eventually leads him to discover the suspicious lack of gods around which are the breadcrumbs leading to Gorr’s crusade.