@imp3tuz If your area is totally unmapped - no streets or buildings - go to osm.org and click Edit. That opens the browser-based editor called iD. Follow the walkthrough.
If you want to add all kinds of details and a gamified experience, see StreetComplete on Android. (The closest thing on iOS is Go Map, until the StreetComplete iOS port is finished.) StreetComplete also supports making photo notes which can be used with iD.
MapComplete is another easy way to add points and notes from your phone and desktop. Uniquely, it also allows you to add photos, ratings, and reviews for places. If it’s too slow on your phone, try the native version.
If you have questions, search wiki.openstreetmap.org. If you still have questions, ask on Fedi or on the OSM XMPP channel
https://mastodon.gamedev.place/@imp3tuz/114929877915497836