Here's the thing: even a casual deck not intended to be competitive needs to have certain basics covered, or else it's just a mess that loses just about any other deck and it ends up being frustrating to play.
> For starters, your Pokemon/Trainers/Energies proportion is WAY off. With some very limited exceptions (such as BKT Typhlosion) no deck should ever run 25 energies. Your hand will brick way too often; more often than not you will find yourself drawing dead. Even energy-heavy decks rarely use more than 15 energies, and a lot of normal decks use between 10 and 12 . Having mixed energy costs means you need to take more energy cards, but more than 15 is not worth it. I don't know how many of each you should take since your Pokemon lineup also needs some work, but at the very least I'd aim to not have more than 15 to 16 energies.
> Same goes to your trainer count, 15 is way too little. Trainer cards are the bread and butter of any deck, so taking the right trainers (and a good amount of them) is the key to making a deck work. Right now this deck is lacking on both fronts; you're not taking enough trainers, and the ones that you did take are not very useful. Specifically:
-If you're playing Standard, you should be using Cynthia x4. There's no two ways around it, many times Cynthia will be the only method to refresh a bad hand. Tate & Liza or Judge can also refresh your hand, but Cynthia gives you a 6 card hand. You can use these cards on the same deck, you'll have plenty of space after removing the excess of energies.
-Guzma is also a must have for any deck right now. Being able to take any of your opponent's Pokemon (while having a switching effect as a side bonus) is just way too powerful of an effect to pass on it. I this 2 or 3 is a good number of Guzmas.
-I'd remove Hau altogether. I'm honestly kind of sad to see that they are still printing the "draw 3 cards" card for every single generation. This thing is a big noob trap that's completely unviable outside of Theme Decks, because every other draw or reshuffle card out there does a better job than it. Take some Cynthias instead; cards like Sightseer and Lillie are also good (although Lillie is a lot better if you have a Tapu Lele-GX to use her on your first turn. Otherwise she's kind of meh).
-Since your entire strategy revolves around placing Stage 2 Dragons straight to your bench, you should use a Lance Prism Star. It could end up prized and will be hard to find without Tapu Lele-GX, but on a deck like this it's still worth taking one.
-Lady is really not worth taking. The only energy you need to have lots of in your hand is Fire Energies for the Darmanitan to attach. Fiery Flint accomplishes this much better (it doesn't use up your Supporter of the turn). For the other energies, you can simply draw them, and reliably so if you improve your Trainer lineup.
-You should be using some amount of Ball cards. The only one that's a must have for almost every single deck is Ultra Ball, but other than that you could consider Nest Balls (to get the Basic Pokemon you need benched ASAP) and maybe Timer Ball (sort of unreliable since it has a 25% chance of failing, but it can be useful on decks with a lot of evolved Pokemon).
-Being a dragon deck, you really need to use some Mysterious Treasures. For dragons, it's basically an Ultra Ball that only requires 1 discard.
-You need some Field Blowers. 1 or 2 is a good amount. You can keep Stadium control with your own Stadium cards, but sometimes you'll urgently need a way of removing tools.
-You also need some Rescue Stretchers. 1 or 2 is also a good amount. Being able to recycle Pokemon is somewhat of a necessity.
-Some Pokemon Tools would be good here as well. You have a few choices. Whishful Baton seems like it would go well with this deck since you usually have to deal with high energy costs and your only form of energy acceleration requires you to use up your attack of the turn, so this can carry you out of bad situations. Choice Band is a really good generic Tool to take on any deck as well, so you can consider it.
> As for your Pokemon, there's a few things you could consider while still keeping this as a casual deck. Since your strategy revolves around benching Stage 2 dragons, Dragonite-GX seems like pretty good choice. The downside is that it can be a bit sluggish compared to the Stage 1 Altaria, but you won't have to deal with RNG so that's definetely a plus. In an ideal scenario, Dragonite-GX's GX attack + Lance Prism Star could fill your entire bench with Stage 2 dragons in an instant. You would need some Rare Candies to make this work, but I can see this being a thing even if it's somewhat sub-optimal.
I'm leaving it at this for now because I'm kind of out of ideas, and it seems like I got Greninja'd so there's more advice incoming anyways xd If you have any doubts feel free to ask again. If I can think of something else, I'll make sure to come back and post it here.