[Developing RAW introduces noise?]

I just came on to the forum looking for the a solution to the same issue! I'm new to Affinity and photo editing in general, so I was thinking maybe I'm doing something wrong.

 

I have a MacBook Pro (Mid 2009) 2.26 GHz Intel Core 2 Duo NVIDIA GeForce 9400M 256 MB

I've been working with two cameras: Canon EOS 6D, & Canon EOS 30D

[Some of the features don't seem to be working]

I'm new to Affinity. I've watched the videos about using RAW but  every time I go to develop all the adjustments I made disappear. I've also been trying to use the blemish tool and that doesn't seem to do anything either. Tried using the unmask sharpen filter and nothing happened, even after I pressed apply. This is very frustrating because other things work really well.