You need to be more specific, all cars have camber, positive or negative. I suspect you're trying to say you want more negative camber, which is likely difficult and stupid to do as the car probably does not have an adjustment for it. An alignment will only correct the toe but it must be done if you have lowered the car.

you should have a wheel alignment done this will ensure that all the wheels are straight. its recommended that you do this after any suspension modification (lowering in this case) while this is being done you could ask the mechanic to add the amount of camber you want (in degrees) and then you know your safe to drive worry free.

On a side note adding camber does cause excessive wear as there is less tyre contacting the road as a result you could find your wearing tyres out in just a few months.

Obvious troll here - you can't "stretch" tires onto a rim that's a larger diameter than that of the tire bead. Not possible.

your suspension was just hanging unloaded.

Ok, so I have a 2010 ford fiesta WS MK7, and I recently put new rims on it and I went up an inch in rim but down an inch in tyre size (stretched tyres) and when they jacked it up on the hoist I magically got camber. How did this happen? And is there any possible way to get more camber or camber arms for my car? I have also lowered it