Mastodon

I am trying to get into Mastodon (never really used twitter before but I am curious about the fediverse) and it has been noticeably difficult to search for topics and content. Most search queries turn up blank or only with one or two posts. Some hashtags appear as suggested with "0 people talking" and indeed, they are empty.

Am I searching wrong or is it just more difficult to search across Mastoson?

I am using the Mastodon app for Android and joined a spanish speaking instance, if that is helpful.

Thanks!