To view your Immich photo album on a web browser, head to http://photos.dualarrow.com and log in. From there you should be able to figure out most of how to use it.
If you want to share your photos with another user of Immich, Log in to the web site, click on your initial in the top right circle and you should see a menu. Click on “Partner Sharing”, click “Add partner” and select the person you want to share with. That person will only have read access and wont be able to edit/delete any of your photos.
There a LOT of features in the system. It can find duplicates and let you choose which to keep (I find it does a very good job) and you can make up albums if you want too. There’s also a world map that gets the EXIF data from the image to determine where in the world you were and groups them on the map. In the search options, you can also type things like “beach” to see all beach photos, or “dog” if you want all your dog photos.
There’s a ton more documentation if you feel like reading it at https://docs.immich.app/overview/quick-start select the “Features” entry as a lot of the other info is on installing the server which you wont be interested in doing.