IngestInsert a card and it appears in the sources list with its name and free space. By default Ingest opens it for you. That is a setting in Settings → Transfers, if you would rather it just sat in the list.
Reviewing does not change your card originals. Ratings, keywords, renaming, and Finder tags are applied to copies, not to files on the card. Source files are deleted only when you explicitly request it after copies have been verified at every destination. That holds however you opened the card, including when you open a folder that happens to live on one. Metadata you add while culling is remembered and applied to the copies during ingest.
If a card does not appear, check that it is mounted in Finder. Ingest looks for a DCIM folder to recognize a volume as a card. A card formatted by something other than a camera may not have one, in which case open it with ⌘O as an ordinary folder.
To eject, press ⌘E. Ingest closes everything it has open on the card first, so eject does not fail with a file in use. If macOS still refuses, another app is holding the card. Pulling a card without ejecting does not crash Ingest. It notices and closes the source.