Hi,
First, congratulations on your first paid job!
Ok, this is what you need to do:
Get a list of the visual elements your client wants for the site.
Get a list of the functional elements he/she wants - do they need any special capabilities, like a contact form for example?
Armed with this knowledge, look around the web, check out sites of a similar nature and also go to template collections .. for ideas.
Once you have a few ideas, just quickly mock up something in Word (any program you are basically familiar with) using placeholder dummy text and images. Just let the client know that this is for feedback only … just in case they get nervous that you are bringing them pdf's or screenshots of the layouts.
Don't try to learn Photoshop and web design at the same time - you are just making headaches for yourself for no good reason.
Final tip: for your first web design job, don't expect to make much money per hour. In fact, you are a lucky one who is being paid to learn. So consider it an opportunity to develop your skills.
Stef