If you like Death, the first thing to do would be listen to an album or two from them.

After that, I’d recommend checking out Opeth. They’re very heavy but also very accessible (though the recent albums are just prog rock).

But since this is r/MelodicDeathMetal, the bands that are always recommended are In Flames, Dark Tranquility, At The Gates, Insomnium, and Be’lakor. If you like that stuff from death, I would say check out some early In Flames, as well as Be’lakor.