I'm afraid that I don't know any kids-safe spaces for budding VN readers or writers, but you can use VNDB to search for visual novels with an appropriate age rating. The following query returns all VNs with a release rated for 3-8 years, excluding any that have a release rated for older ages:
Though I will caution that a lot of these are either self-reported by the authors or just guesstimates by the person who added the VN to VNDB.
And I will caution that you should never trust it when a visual novel is described as "all ages": For whatever reason, the VN reading community has settled on using that term when we mean "no explicit sexual content". Beyond that, anything goes for an "all ages" VN. The search link above has a minimum age rating of 3+ for that reason
https://vndb.org/v?q=&ch=&f=02N1802a48a23N19a38&s=26y
Though I will caution that a lot of these are either self-reported by the authors or just guesstimates by the person who added the VN to VNDB.
And I will caution that you should never trust it when a visual novel is described as "all ages": For whatever reason, the VN reading community has settled on using that term when we mean "no explicit sexual content". Beyond that, anything goes for an "all ages" VN. The search link above has a minimum age rating of 3+ for that reason