Is this your first Line6 product? Ive been around em so long that the tweaking is second nature. ALL digital products have a specific language and once you get used to it, the stuff is real easy. Strymons have their own way of how to create sounds thats so different from others that it takes me a bit to re-wrap my head around it.
Options can be overwhelming. Make it as simple as you can for yourself. there's a site i saw with the "top 5 things you need to do when moving to the helix" help sort of checklist.
Also, look for presets you can download which help show you how tones are constructed.
As far as the fizz, double check the cab sim is on on that preset and most recommend turning off the Global EQ.
GET the helix editor installed on your computer. Its much easier to use, even as easy as the screen is to work from