You want to play DDR? We'll ignore the physical limitations for this.
First off, do you have an arcade near you? If you want to play New, Modern DDR with all the bells and whistles, that basically needs to be a Dave & Busters or Round 1, since those are the only two places that can officially use Konami's network service here in the US. Options are probably even more limited outside of the US and Japan. If you're really lucky, you have a local arcade that uses a private network.
Of course this involves having transportation, and money to play. Pay per play per round adds up fast.
What if you want to play at home? Konami did make an official home version... but it's all in japanese, requires a monthly subscription, and is super limited. And there's still extra pay-to-have-normal-features stuff on top of that. (Also they will sell you a soft pad which unlocks songs that can only be unlocked with it for 17,000 yen)
You can of course run stepmania et al, and getting official or unofficial songs for that is trivial. But you still need a controller. More on that in a moment.
If you really want the actual, "normal" arcade experience at home, you must deal with some of the most gatekeepy people you'll ever meet in the Arcade Rhythm Game Piracy scene. It sucks shit there.
The old console releases, "CS" in gamer words, still exist and work fine. Playing them in emulator takes a lot of work to get the timing working as intended sometimes, but other than that they work good. Lots of good CS exclusive songs out there too.
And, once you have everything running.... you need a pad. "Soft pads", those cheap vinyl things that came with DDR back in the day, still exist and you can buy them used for cheap. Konami will sell you an overpriced one if you must.
Used pads exist, but you have to know what you're looking for, and what a good price is. You're very lucky to get anything good for under $300. A company in poland will sell you a pad for around that, give or take a bit (it's been a while since I checked), and it's alright. Not great, not awful. Want to play doubles? Hope you got two pads. And they don't move around when you use them. And you have a way to connect them.
Oh, hope you have a space with an actual solid floor to play on. Any type of raised floor is right out. And you have to be able to make noise, both from playing and the music, since you can't play with headphones on. Well, you can, but it's a bad idea.
What if you want a good pad? Like a good good pad? Step Revolution will be happy to sell you full arcade pads for around 1800 a side, before shipping, if they're actually selling them at the time. Or you can try to find actual DDR arcade pads, of which the pricing varies wildly with condition. Generally if you get two side for under 2 grand you're doing pretty good. That may or may not come with a cabinet, of which the quality is another huge question mark. Step Revolution will also sell you an entire cabinet for under 10k, if you wish.
All of this is why I hate DDR. I love playing DDR and I want other people to share that enjoyment too, but actually playing it just fucking sucks unless you Have The Right Stuff. I'd rather people find something fun to do that doesn't involve buying crap.