Yay! Congratulations!
Here’s a long-running forum thread where people post many of their achievements:
https://forum.inaturalist.org/t/inat-milestones/31211
We are always equally thrilled by someone’s first 100 observations, as we are by someone reaching 1000 species, or 100,000 IDs.
I can remember my excitement at reaching 100 obs, or a 100 species, although that was several years ago, and long before I discovered the forum, and all the supportive folks here.
Welcome to iNat and the forum!