When I was fairly new, I was doing Elemental pulls. Looking back, the benefit of hindsight makes me feel that those pulls were a waste of gems (to me).
As other have already noted: wait for Atlantis portal.
And check out that thread linked above, Advice for New Players. I’m sure it probably says it in there, but… focus on getting your training camps leveled up, because that is how you can stock up on 3* heroes, then eventually 4* heroes, and then also eventually 5* heroes. Over time, you should get just about everything that you could’ve gotten from the Epic or Elemental Summons. Atlantis pulls will give you the more special stuff… maybe… sometimes… not guaranteed.