It's hard man. Sorry to hear. I've had interest in Palutena, but do not even use her as a secondary, so I can't give you tips on the character, but I'll try to give tips on how to improve.
I do play Palutena a little, and know that she does need a lot of skill to play. Like a lot! I suggest to keep her as a secondary for a now, and have a different main to learn off of at first. I also suggest looking how other great players use Palutena, like Aerolink. (He's the best Palutena in my opinion!)
I also suggest testing customs out (they're very good with Palutena), but you can't use them in FG so you might have to go to a friend's house, invite a player in an online lobby, or go to tournament.
Learning the game can also be difficult. I suggest training mode, watching a lot of YouTube, twitch, computer playing, and just simple online as your ways you to learn. Though online can give players bad habits, if it's your only option, use it. If you can, try to go to competitive meet ups, even if you get your butt whooped!
It will take a lot of matches to get improvement. I've been playing smash 'competitively' for about half a year and I think I'm learning fast, but I only do average to decent in tournament, and will probably stay at that skill level for at least another 6 months.
The more you play, lose, and watch, the more you'll learn, even if it doesn't seem like it. Also, be confident in yourself, because if you're not it'll be harder to learn.
There was several times where I wanted to quit because of obstacles, and I'm currently having trouble picking a main, but you can't give up! Give it some time, and you'll see some results! I know I certainly have, and I'm expecting some later!
Another thing that helped me was trying to find some taste in every character! And you're own taste!!!!
It can be similar to some one else's, and you can borrow some combos and skills, but having your own mindset that is different from character to character is important, and I believe it might help you learn. Remember to keep pushing Palutena more than anyone else though! Playing with every character and play every playstyle equally will definitely help overtime!
Remember, the game is about smarts, wits, knowledge, and mind games! You might have the best combos out of everyone, but you could come dead last if you don't have the smarts, and practice them A LOT! It's hard, and that's actually what takes most time to learn. It could take years!!! (A lot of players here on smash boards have the combos and options, but lose mostly because they practice too much combos, and not the actual thinking! I'll admit that I have the same problem!)
Most of all, have fun! Take a break if it's not! If I'm already warmed up, I usually play my best when I take a break, and a hiatus for some time won't hurt! Hope some of this advice helped!