A few things come to mind.
-Embrace the idea that, at the moment, you're not good at the game. Sorry, but it's probably true. Keep pushing yourself to be better, don't stop and say "I think I'm a good Poppy now" or similar. Be humble with yourself.
-If you're losing, don't lose hard. Especially as a new player, and a lot of times throughout your League career, you're going to be outclassed in lane. Don't be that guy that keeps trying to win an impossible fight over and over; back off, give up some farm, and focus on taking what farm you can get while being close enough to your turret to be relatively safe. Ending a laning phase 0/3/0 with sixty CS less than your opponent is rough, but it's a hell of a lot better than ending it 0/9/0 and giving up two turrets.
-Understand that Bots are not currently good enough to perfectly prepare you for real players. Intermediate bots are fine practice for learning basic moves and combos with a champ and getting the hang of CSing, but in terms of micro-intensive fights and objective control, you're getting nothing meaningful from the experience. You'll need to learn that stuff the hard way.
-Don't get discouraged. League has a rough community, especially at lower levels. If somebody is giving you a hard time for underperforming due to being new, mute them. That said, some people may try to help you, and some might be rough about it but still give you valuable tips, so I leave it to you to find a balance.
-Find friends to play with, if possible. Attitude>skill. League is infinitely more fun with people who are also fun to be around, and it's easier to learn the game when you're having fun. I think people who don't make a happy environment for themselves dwell on their failures too much to improve on their skills, at least from what I've seen.
-Read guides and watch videos. League has a massive learning curve to summit, and doing so on your own without help is going to be an arduous process. Read up on build guides and general strategy, and watch videos both of the game as a whole and of your specific champion.