Hi @mohsen_ej,
This question has been answered a few times on the forum already, a quick search of “adding taxonomy to biom” for example gave me 2 useful top hits.
You can either start with this tutorial, or also see this one I made some time ago that should still work, you’ll want to just follow the first few steps and don’t worry about the BugBase specific steps.
As for your second question, if you only have 3 features across all of your samples I would imagine that yes there is something wrong. Unless you are expecting only 3 features for some reason. There are lots of reasons why this could have happened in your workflow and it is very hard to troubleshoot without have additional information. Could you please start a new thread (as that is unrelated to this issue) and provide us with detailed information about your whole pipeline up to the point where you get your feature-table. Sharing your table.qza would also be very helpful for troubleshooting. Other information like sample-type, target region (i.e. 16S V4?, V3-V4?) and sequencing method will also be very helpful.
Thanks