I recommend easier picks, malp and sion are pretty straight forward, but it seems like you'd benefit from playing a lot of garen, I say this because if you're silver, it's just basic mechanics are holding you back.
You're average CS per minute is 4, and that's not really great.
You're goal is 6 minimum, 7-8 is best, but sometimes not realistic.
By losing a lot of CS, you're either just missing a lot, or trying to harass to much. Missing cs is huge, because by the looks of it, your opponent automatically has a advantage because they have more CS, meaning they will trade better, and have more items.
So to better understand the game, I recommend

Garen is the simplest you can get. Liss and vlad are both great because they're safe laners, and they have big influence later in the game(vlad ulti and liss lockdown CC ult)
I'm a veigar 1 trick, and I've gotten much, MUCH better at the game. I'm going to hit diamond next season, compared to being hardstruck plat, and its because since I only played 1 champion, I didn't need to focus on my champions mechanics, and was able to focus more on the game itself, plays, shotcalling, etc. 78 games, and a 68% winrate.
In the end if you're anything below plat, it's just because you're not mechanically strong as you might believe yourself to be, I tried a smurf this season, started silver 3, climbed to plat 5 in 2 weeks with a 90% wr.
If you want more tips or help, feel free to PM me, I'm NA CST, so I'll be asleep after this post, but I'm always down to help. I even do coaching for free if you send a VoD, I'll review it, point out issues I see, and you go from there.
Goodluck summoner.