Hi I would some advise on how to sort this mark out on my bumper. Would I need to rub it back and fill it and then spray it. Never done any of this before. 

Is there an indentation? If so might have to call someone to remove it or look at methods of doing it yourself. If not run your finger on and off the mark. Can't tell from the picture but if that bit is a scratch or paint transfer a hand or machine polish might get it off. 

It’s a indentation. Thing it needs rubbing back filling and then sprayed over. Never done that before. 

Good luck Haha. You'll never get a finish you're happy with by using rattle cans and spraying outdoors. You need a decent sized air compressor (around 100 litres) that also has a high flow rate (at least 14cfm is recommended). Even then it's an art that will take more than 1 attempt on your first job, aswell as a lot of wet sanding/ cutting/buffing.

Personally I'd leave it as it is. The picture you've taken looks quite close up. You probably cant tell stood a few feet away as it's still red.