I have an F70, and I'm also new to detecting. I'm not the best to give advice, but I asked the same question a few days ago.
The answer I was given...'it depends'. What type of ground are you searching? Amount of minerals, trash, coil type and experience level? It's not a direct answer, but the correct answer. My settings reflect the reality of location and ability.
I have only hunted trash filled urban parks. I have an 11"DD and a detector (F70) that exceeds my ability. I use delta tones, because I want to learn sound feed back. For the most part, I stick with an all metal setting. I have my SENC and THRESH dialed back a bit. I get a butt-load of audio feedback, but skip big trash. I have slowed down my sweep and spend more time identifying targets.
I don't know if my advise is correct, but it's working for me. Press your buttons accordingly. Best of luck!
I know realise; I have spent most of my life doing neither what I ought, nor what I liked.
Mr. Screwtape (The Screwtape Letters)