Air on my 2003 expedition

Hey guys,
So I have a 2003 5.4 expedition and I’m having
some trouble with my air...
So my rear heat / air blow fine and get hot / cold no
issues.
Now my front air is where I’m having problems.
When I turn the air on nothing comes out. No
blowing. But when I am driving cold air does come
through whatever vent setting I have it set to. It’s
not blowing out seems more like forced outside air
coming in? If that makes sense. And it’s always
cold no matter what the heat setting is set to. I
hope I’m explaining this for everyone to
understand.
Any help would be much appreciated. I haven’t
messed with anything yet. Figured I’d get some
opinions before buying things. Thank you guys !