If you are that unsure about very basic maintenance I suggest a bike shop. Not all forks are the same, nor all brake reaches or steering tube diameters, did you make sure everything was compatible before purchasing or was it just
Ebay the cheapest thing?
The wheel setup inside the forks is fine apart from pushing down as said before.
Well, I didn't want to buy a part that didn't fit my bike. So I went to a bike shop with the old part and asked "I want another one of these". To be honest my experiences ranged from bad to awful. In general (about 4 shops) just didn't get it (a new fork? What? Do we sell forks? I don't know I will have to have a look... Hey bob! Do we sell forks? No? Oh, sorry.)
The shop where I got my bike from "ordered" a new one, which took 2 months before I went and took my bike back. The one I got this from took a whole 5 weeks of "we have ordered it, ill ring you back with more information later". To be honest I think they had forgotten... One had no idea what I even meant by fork, even after I went up to a bike on display and pointed at the thing ("This pronged metal object that holds the front wheel on" Answer: "Eh? What?" I don't know if my accent is that hard to understand, I don't have any problem with anything except bike shops and forks!) Eventually they gave me this one - which clearly is not what I asked for (Remember, I actually went in with my old part!)
So my experience with bike shops is generally to stay the hell away!