Don't feel like writing too much atm.
Kirby is hella hard to play if you don't get him, CF, Marth and Kirby feels natural for me.. so I never feel like it's something wrong with him..
I could take out any of these in a tourney match without regret..
Kirby is basicly built up atm with gimmick and people only use them, I haven't seen anyone playing him tourney stylewise or **** style..
Anywho strategies I would recommend is DD'ing and grabgames, Kirby got hands down one of the best grabgames.. every character that challenge him in this aspect can get owned by a simple duck or getting outgrabbed.
So I cannot stress this enough, get the Marth person out you'll need to get the grab mind out.
When you get a grab almost always backthrow the first frame you can, because they will not be able to break out in time if you do it asap and if they do you will probably be in advantage anyways.
Dthrow Fox and Falco's + other characters and techchase them..
Don't be afraid to dthrow people that can punish you for it, some people don't know about it or try to abuse it 'always' so if you do it at a higher % when you'll be able to shield their punish you'll be able to get a punish from their punish.
His utilt, ftilt, jab is easily his best moves on the ground.. his fsmash and upsmash are good too, but not used so often.. upsmash is mostly used as a punish against sheiks lag on upB or random punishes.
Fsmash is a finisher but I seldom kill with it, but first hit with fair to fsmash is awesome on floaties(as it combos) and it works on fastfallers too if they miss their tech/tech in place(that hitbox is out for awhile).
Defensive wavedashing aka waveshielding is too good with Kirby, since he got a 3frame jump + a low posture when he WD's + his shield is good. you can waveshield around when you feel insecure or if you're trying to get him to attack.. WD's to pivot utilt is godsent too.
Combos well strong utilt to strong to weak to weak to bair is great, and if they DI then WD after and keep utilt(yeah I know you have never seen this before, but it's possible)..
Utilt to bair asap to grab is awesome too..
Bair to fair or bair to WD bair is good too..
I can keep listing different combos that's viable but all of these you should know by know.
that's it I guess I wrote alot anyways..
(1 hit dairing a fox/falcos upB at the ledge to slipoff/WD off to inhale for the GAME is awesome)