One way to fight stigma and discrimination based on disability is to reject the label "disabled," and instead use another term that sounds nicer, less negative or limiting ... something like, "special needs," " differently-abled," or most commonly, "person with a disability."
This last approach is known as "person first language," because it emphasizes that above all, we are people, who just "happen to have" a disability. Disability, in this view, is a secondary thing, an add-on characteristic that we can separate from ourselves and look at objectively, as a purely practical matter that has nothing to do with who we are as people. Disability is a "thing" that you "have." It's not an identity that defines you.
For some of us, this way of thinking and talking about disability in our lives works well. It's still probably the most common way that disability thought and language are promoted to the general public. It is the most widely-accepted, "politically correct" term.
In recent years, however a growing number of people in the disability community have gone another way, embracing disability as an important and valued part of their identities. Instead of turning away from stigmatized words and asking others to look away from impairments, these people take them on squarely, affirmatively, saying, "I'm disabled," and talking about "disabled people." Some choose this because it sounds simpler and less fussy, but many also prefer placing "disability" or "disabled" up front, for specific reasons.
For one thing, carefully insisting on "person with" a disability is not only awkward in speech and writing, but can seem a little condescending, as if we need constant reassurance that we are, in fact, people. It also fails to recognize that whether we like it or not, disability is a cultural and social identity, not just a practical matter. The idea here is that we can try to pretend that disability doesn't really matter, in hopes that people will think better of us, but disability does matter. It doesn't matter in a bad way, necessarily, but it matters. Others argue that avoiding or demoting the word "disability" though person-first language and euphemisms like "handi-capable" actually keeps alive the idea that disability is always a bad thing, something to be tolerated and managed, but fundamentally a negative. By accepting "disabled," we can work to change what the word means and the feelings it brings out in others.
Which terminology should you use then?
Your best bet is to pick the terminology that makes the most sense to you, but be open to adjusting to the preferences of other people when you meet them, especially if they have disabilities themselves. Whichever construction or wording you prefer, the worst thing you can do is criticize or lecture to another disabled person / person with a disability and tell them that the terminology they use is wrong.
Language evolves, and so do our own views of disability ... maybe especially our own disabilities. Instead of worrying about getting it exactly right, keep an open mind, eyes, and ears, and appreciate how changes in language reflect ongoing changes in thinking. Shifting expectations can be annoying sometimes, but they are also healthy signs of the disability community's growth and diversity.