Which on do you prefer for beginner photography canon 1300D or nikon 3300
and if possible the pros and cons of each one
it depends on your priority and budget. Let me explain in a few words:
If you intend to use your dslr also for recording videos, then canon might be the best choice. But if what you're looking for is the best photo quality, I'd definitely go for Nikon. Most of modern Nikon cameras don't sport a low-pass filter (AA filter) on the sensor, which (by not having it) will enhance details on your photos (better sharpness).
Nikon comes with a few downsides, like a poor mobile app, and the lack of a lever system inside most of their entry-level to pro-sumer cameras which won't allow you to change aperture in live view. You will have to exit live view, change F number and go back into live view.
Not really a deal breaker for me, but it's something that it's there for years now and everybody's wondering why they didn't fix it.
As for the 2 cameras you mentioned in your question, I'd go with the Nikon though, for it's excellent image quality. Canon is a step or two behind on this matter.
There are pros and cons on both brands Filippo.
Also, both cameras you mentioned are entry-level, but if you can raise your budget a little bit, let's say from £300 to £400-450, you can get something much better, like the Nikon D5300, a GREAT camera, with a GREAT sensor and a fast processor. The D5300 is in the entry-level range only for its price, but as for pure image quality, it's a high end prosumer camera.
I hope it helped.
Cheers from Italy