Hi Sylvia!
You don't need to post anything to particular servers. The servers talk to each other seamlessly, so you just need to post on your own server.
To get a query noticed by more people, try to use all the relevant hashtags you can think of.
If you want your account to get more visibility, here are some hints to help with that: https://fedi.tips/how-do-i-get-more-followers-on-mastodon-and-the-fediverse/
Also, you may want to post queries to a discussion group, more about them at https://fedi.tips/how-to-use-groups-on-the-fediverse/
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