Suit Termux is fine, there are a few threads here on the forum if you want alternatives just search for "Termux".
stupidcreature Hello, I would not suggest installing Termux as it is not officially supported beyond Android 12 (the current version of Android for GrapheneOS is 14).
I don't know about version support but I would imagine they support newer versions if you check the GitHub Actions workflow downloads. For some twisted reason they don't push those to Releases or F-droid, you'll have to specifically log in and download them from the actions page manually.