Learning languages with YouTube playlists is a common practice now. Here are most successful video courses for archiving korean elementary level online via videos. The courses cover grammar as well as some vocabulary.
Sejong Korean basic and elementary grammar and vocabulary
Appealing videos with great visual explanation and subtitles in Korean!
My learn korean elemantary playlist
My elementary playlist with videos from such channels as Seemile, MasterTOPIK, and others. Explanation is in English, also useful for beginners!
Boost your vocabulary and learn how to write about traveling in Korean with this text and translation!