Honestly, start by ripping all those songs off. Try to create a similar vibe those songs you adore have. Do it many times over and you’ll find something of your own in there. That’s the secret of every great band out there. In the beginning Metallica used to rip-off Motorhead and Venom, Pantera used to rip-off Van Halen and Judas Priest, and so on.
It may take a while to get there, but you’ll find your own way of expressing a certain vibe or motif, whether it’s in riffs or just songs in general.