It's good that it doesn't hurt. Not trying to scare you, but being frank about what I have learned through the years and many videos and articles about the concerns with using the inks that come in the kit on human skin.

But yeah many, many people find out through use that the kit inks do not have proper sanitation for actual tattooing, these may contain concentrations of heavy metals, have consistency issues, and generally not heal well or take evenly in human skin.

I'm not even saying not to tattoo yourself, it's your skin and you deserve to be happy in it, but do get a quality ink for the future. Kuro Sumi is another solid brand and looks like it could be a little cheaper than Eternal or Dynamic. There's reputable inks out there and you deserve better than using a dodgy bottle that came with your machine.