What could be some of the causes of large amount of play in my steering wheel? I can really feel it when i'm driving, especially on the highway. What could I do to fix it?

 

Any and all of the steering components wearing out can cause play in the steering.

You need to examine everything for looseness and movement where there should be none:
Ball joints
Tie rods
Track bar
Drag link
Sway bar links
Steering damper
Steering gear

I'd go through and examine everything. There are plenty of write-ups/youtube videos on checking each of these components.
Jack the front end up and have an assistant turn the wheel and see if something jumps out at you.
If you haven't replaced any of the above items in the recent past you could have multiple parts worn out. Hopefully the steering gear is OK because that's a real beast to replace and there's a high chance the replacement parts are bad right out of the box.

 

check the steering shaft, under the hood.
There is a rubber isolation damper in the middle, and then down by the box is another bell shaped joint.
My boys MJ someone had nearly pulled the rubber out of the isolator, curious way i found it. Turned the wheel to lock and pulled and could keep turning the wheel as it was nearly in two pieces under hood.

 

I've never tried this personally, but when I was buying ball joints on Amazon it suggested this:


(It's a RuffStuff Specialties tie rod "cure" if that link doesn't get you there.)

That claims to tighten up the steering if you're getting twisting in the drag link.

 

^^ X2..... that's exactly where to start and go down the entire list and carefully inspect each one. Don't stop at the first sign of wear and assume that's your entire problem.

 

Would it do that if i needed a wheel alignment as well?

 

A reputable tire shop won't even do an alignment if any of the above mentioned parts are worn.
You might take it to the tire shop and ask them what needs to be done before they'd align it.