Hi Angelica,
Where are you located? Do you currently own photoshop? It might be that there are inexpensive courses near you. It would take all of 1-2 hour at the most to get you comfortable with the level of work you need. This help is availablr inentry level digital photography forum and you'll get lots of help there.
This is not like software programming. Everything is pretty simple and rather intuitive once you are shown around the playground, so to speak!
Concerning lighting, the simple way is to have the dogs on a dark sheet and near a window. You can use a large white card (or reflective cloth disc) to direct more light to the front of that setup beforehand and then get your dogs to snuggle together again. It's like a date, they may need a lttle alcohol first! Just joking! Don't do that!
If you choose a fabric that doesn't get creases you are better off. Gentle overlapping folds in a covering can be very attractive. However, there is no purpose in having the background of your dog portrait, white and bright (unless you have that in your artistic design), at it might make the b.g. more important than your dogs!
The important thing is that one takes this picture, prints it out, puts it in a ring binder and then mark up the picture with what is good and what you might improve.
The start of a great picture Angelica is the concept! That's really good!
Asher