I think the easiest way to learn makeup application is via our tutorial section. You won't have to admit to anyone that you don't know what you're doing, and you can stop the video at any time so you can see more clearly what is being done.
Start with a few colours of eyeshadow in the same colour range (beige, brown and dark brown for example) and then take a look at some of the eye shadow
tutorials.
If you still don't feel confident after you've tried some of the tips and tricks suggested, THEN I would go to a department store and ask for a makeover, and ask for lots of assistance with how to apply or anything specific you're having trouble with.
as for the acne, have you thought of seeing a dermatologist or your doctor to ask about medication for the acne, or any kind of treatment for the scarring? if you don't already do it, try a simple skin care routine such as cleanse, tone, moisturise, and see if it helps with both the acne and the scarring. There are some pretty cool recipes for face masks on this forum, so do a
search and see if you can find anything you like the look of.
Best of luck, and I hope this helps!