What champion should I get? (New player)

Hey all, I am a new player and I am really looking to settle into a permanent role. My first champ was Zed which I bought with rp and while I had decent success with him, he was not fluent enough for me and i just could not feel like I was making the most of him. I gave him up and just recently swapped him for ekko who I am just starting out with. As much as I enjoy him, I do not feel like I will main him, rather he will probably just be one if my sides. My other champion is Shyvana who I really enjoy but like Ekko cannot see myself maining. Of all the f2p champions (anivia was in my first week), the only one that has stuck with me is ahri but i don't like her enough to buy her.

For my skill level (lvl 15 summoner), I normally get a solid kill-death ratio but there are times where it goes through the roof and others when it goes through the floor, normally when I use a new champion.

So, basically what I am looking for is a champion i will love and cherish and play the living daylights out of. Of the champions I am considering, they are as follows: -Zac:Via crafting with essence. I do not play jungle and do not understand it as of now but i am sure i can learn. However, how well i can do it is another thing. But basically i like the look of Zac and have a champion shard on him. I also have a tendency to over extend in lane and are rubbish at last hitting so maybe jungle would be a good place for me -Rengar: See Zac on my jungling skills however I really like the look of him. A really good one absolutely destroyed me in a game however instead of being annoyed I was in awe by his speed and damage. However, he does look hard -Gangplank:Looks good but idk about playing him fulltime -Gnar:I do like the look of him but he looks like he has a high skill cap and i am looking for someone who is a bit more permanent (if that makes sense) -Jhin and Lucian:Adc is my worst role by far but these two look like the cream of the crop -There are a couple of other options however these are my main ones atm anyway. Sorry if i rambled on or was unclear. Thanks for the help