My advice is don't worry about tunes righ now. Learn to drive first, improve your driving skill and try to learn some competition driving technics (is not the same that driving your real car in the streets). You can learn lots of things in this forum, but first you need to practice, practice and a bit more of practice. Then you will start to feel what's going on with the tyres, the suspension, etc... And you will be able to compare your new knowns with your experiences...Try diferent cars and learn to feel the diferences in performance. I sugest you to start with low powered cars (like your hachiroku: it's a nice car to start)
First step is learning the driving lines: when or where to brake, when or where to turn, etc. Try to set a good time in some tracks, and then try to improve your time...
Then you will be able to feel what happens if you change a value in your setup.
If you try to learn all in a rush you will get confused/frustrated. So start by the basics.
There's a lot of people who is playing and posting about this game for years. You can understand that everybody here started in your same situation, and most questions you have were answered before... So come often to the forum, read the sticky threads, try to look for some specific questions... This site is huge, and there's a lot of info here... You're in the correct place!
Enjoy!