Will Apple give me a new iPhone if they can’t fix mine

There is a $29 deductible.

If under AppleCare+ Apple is unable to repair your phone (which is unlikely), for the deductible you'll pay, they'll replace the phone, but typically NOT with a brand new phone. They usually provide a refurbished, but like new phone of the same model, color and storage options. You do not get to choose the color, etc. They will provide you the same model phone, including color in return. But they'll likely be able to fix your phone if all you did was break the back glass. Any other damage, which is cosmetic would not be fixed.

IdrisSeabright gave you a good answer to your how long question.

can you give a new phone i have a tablet

No

Embersight wrote:

How long does the full process take? And how do I know when they are done, the Apple Store has my phone, or do they give a temporary, or you just stay in the store for the time it takes

That depends on a number of things. It depends on how busy the store is (never go without an appointment!). It depends on what they do. If they look at it and decide it needs to be replaced and they have replacement stock on hand, you might be out of there in 20 minutes. Only the store you go to would have any idea.

This was the case for me. I had a crack on one the glass in front of the camera lens. They cannot replace the glass. The repair basically gives you a new phone. The only part they can reuse is the screen and the camera. I paid the deductible and was happy that I got a new battery replaced as part of the repair. Back to 100% battery health.

what if the back glass in the camera area is cracked, not the camera itself, will apple replace it or fix it for free if I have applecare +?

Was it the exact same model and everything? Does jt work fine like your previous iPad?