The green is tricky. I think maybe the safest way is to add a Solid Color layer of lime green, and change its blend mode to "Hue", then mask it on carefully.
Ok, that's one less thing to worry about.
For changing the red to pink, I think simply a Hue/Saturation layer, choose Reds, and enter roughly:
-10
+35
+40
for the three sliders.
Also, I just noticed that your file is untagged (doesn't have a colour profile attached). This is quite risky. Always make sure you have this checkbox checked when saving your files:
Hi Jessica, I'm sure we can manage this. Go ahead and do your raw processing as normal, then post the photo again, along with a 100% crop of the cake so I can see the colours close up.
Also, remind me which version of Photoshop you have?
I understand why you say "unfortunately", but of course it's a good thing to have technical problems out of the way.
It should only be a week or two until you have an opportunity to upgrade the Raw Class.