Been listening to that song Riptide on YT and the chords are Am/ G/ C/ C ( no Gm and capo up 1st fret ) but the strumming pattern is with 16th notes and C and G are far from the easiest chords, I would scale this song with 2 guitars here in GT so not a beginners song, mayby you want to much to quickly and without structure in your learning or no method you are not going to get far quickly, no matter with what you want to learn.

Herman