Seems like it is mainly a juice problem, but one thing to consider imo is that the starter kit batteries are a bit under powered to appreciate a Nautilus mini, or most other dual coil glass tanks. With a 650mAh battery your peak performance time will be when the battery is fully charged, and if those are anything like my kanger starter kit batteries that I started on then a brief 6-8 vapes before it dies lol.
I would suggest your ego type batteries to be in the 1100mAh vv - 1600mAh vv range if you are planning on using a solid tank like the Nautilus mini or Aero tank with an ego type. I think if you got the coin later and you find you really enjoy vaping over cigs then a solid purchase would be the MVP2 paired with glass tanks especially the Naut mini. I am loving this tank atm. .
Of cource if that starter kit is decent then really at this stage while you are settling in you should just need to have some various tasty juices you are checking out paired with multiple decent cleros. If the vapor and flavor is satisfying then you are doing well imo.
Juice imo is the most important I prefer the sweet dessert flavors. When first starting I tried to emulate the cig more than I do now, but once you can lock onto some nice flavors profiles to your liking there will be vast variations you can try.. Also with juice if you run a higher vg the cheaper clearos might not perform as well as with say a 50/50 blend. I like the 30/70 pg/vg range.
Just my two cents. Best of luck to you.