I play Riven and Fiora and Jayce I wanna get gold or silver with them is that possible?

Seems legit.

No you're bad and you should feel bad. The thumb rule is to know how to play 5 champions that aren't commonly banned really well, one for each lane(support,jungle is included as a lane) and then another 5 champions that you are okay with or really good incase the pick they chose counters you and finally get familiar with all your champions so you can counter pick.

so your still rather new to the game - alot of gold and silver players have played dota and or played this game since beta so don't expect to magically play through ranked as soon as you get to lvl 30 and expect to be 1700 elo + . Because realistically its not going to happen. But if i was you i would set an amount of normal wins before you start playing ranked games. ie 800 wins would be a good amount. After 800 wins you should be skilled enough to do good in ranked and have enuf runes, champions- general knowledge of the game. ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Having 4-5 go to champs is always good - but you can't go wrong with trying new champs and finding more champs that you are instantly good with. i have seen alot of people make the mistake of playing ranked after 200 normal wins. And they usally slump to around 900 elo. After you slump to this you have to go through the pain of carrying urself out of elo hell.

We need support, k riven support.
we need mid, k, new meta riven mid.
we need top, k, dodge