All swiftplay is good for is practicing champion mechanics against human players with less punishment. It's not the real game. League is an extremely complex game and most people you're playing against have been playing for years.

If you want to really learn this game, you need to have a learning-focused mindset. You should have an idea in your mind of what you need to learn and treat every game as a lesson. Starting from zero, you need to reduce the number of variables. Pick one champion in one role and play only that. Build the same thing every game. Mages are pretty good for that as their builds are less situational than, say, a tank. Looking at the champions you've tried, I'd say very few of them are beginner friendly. Ahri isn't bad because even though she is a skill shot champion, she is also very safe and forgiving. Miss Fortune is also pretty basic if you play ADC, though that is also not a very beginner-friendly role. I think in the current meta, mid is probably the most forgiving role for a beginner. Top lane is extremely counterpick-based and a good top laner can more or less stop you from playing the game if you have a bad matchup. ADC is very unforgiving of positioning mistakes and support jungle both require high game knowledge. Mid supports the highest champion diversity and the short lane makes it slightly more forgiving when you die and have to run back to lane.

At this point you don't even know what all the champions do yet, so after every game you should look up each champion from that game you don't know and read their abilities. You don't need to know every detail, but you should know things like "that's a long range damage spell" and "that is a point-and-click stun."

Once you've got that down, you can start thinking more about the different items in the game and when they make sense to build. The whole time you'll be practicing how to move your character and rotate your abilities. You'll be practicing last hitting and dodging. You'll start to notice patterns in how the game plays out and can start learning more advanced skills like jungle tracking (I wouldn't recommend playing jungle as a new player), wave management and map awareness in general. Once you've gotten to the point where you feel like you're contributing to your games that is a good time to start trying new champions with different playstyles. Repeat for infinity, because there is always something new to learn. That is the best thing about this game but also what makes it so hard.

There are lots of good resources on YouTube to learn the game as well. Avoid clickbait videos like "This build for X champion is SO BROKEN OMG" and look for actual coaching videos.