newer modern forks are threadless right? i should have no problems replacing a threaded fork with a threadless fork right? just swap and get a new stem and things will work? or not?

It's never as easy as that.

Almost all threaded forks have 1" steerer tubes. Threadless forks are mostly 1 1/8" steerer tubes. There's exceptions to both so you may be able to find the replacement part that you need. If you acquire a used fork, be very careful about the length. That's a cut-to-fit part and you almost always need more steerer length than you think. You'll also need a threadless headset.

Yes, but you're going to need a new headset as well, unless you own a Chris King.

+1

Are you actually trying to convert your bike to threadless, or do you just need a new fork? If the latter, you can try finding a threaded fork at the same length and diameter as your old one. This will be either 1" or 1 1/8" (diameter). If you wish to convert to threadless, you need a new headset and stem as well. And the steerer tube must be quite long to accommodate the new setup.

fork , headset and stem. 1" threadless is a bit tougher to find..,
all newer bikes use 9/8" (or some, more)

If your fork is OK keep the threaded headset,
and use a quill to threadless conversion plug, and a threadless stem.

yeah, i could use a new fork, current one doesn't have a brake hole

Well there are missing things in here, are u talking about 1 inch or 1 1/8 inches fork**********? With any of those u will need a new headset, new stem for sure and maybe a new handlebar as well.