If you're using Mastodon on a computer, there's an optional "advanced" mode available on your server's website.
By default Mastodon uses a simple single column, but advanced mode is a Tweetdeck-style multicolumn interface that lets you add as many columns as you want. This includes a special pinned hashtag feed where you can combine, require or exclude particular tags within a single feed.
To find out how to activate and use advanced mode, click here:
➡️ https://fedi.tips/how-to-activate-mastodons-tweetdeck-style-advanced-web-interface