I need a cake that is good for carving, shaping, and sculpting. Some say a pound cake recipe is good. But what if I want to do different flavors like, (Chocolate, red velvet, etc). How would I put those flavors in a regular pound cake recipe. Also can I use any pound cake recipe in any size or shaping pan? How would I do all of this?

PS...Im a beginner  

so the idea is to start with something like a pound cake and learn as you go -- red velvet is usually crumbly prone to be a little more difficult keeping those crumbs in check -- baking carefully so it does not get dry -- so it just depends on which way you want to go -- using a pound cake first would be more user friendly but using red velvet first would test your newly developing skills and you might learn more --

this chart will give you pan sizes and batter amounts among other important things like number of servings

http://www.wilton.com/cms-wedding-cake-data.html

it all depends on what you want to do I made a topsy turvy cake, a sculpted gravity defying tier cake that was alternating layers of strawberry and red velvet filled with fruit filling -- 

so you just take it one step at a time starting with one thing and you'll step by step get enough experience to do the more difficult cakes  -- here's my favorite pound cake recipe

http://www.foodnetwork.com/recipes/trisha-yearwood/cold-oven-poundcake-recipe.html

I use a poundcake recipe and it works for me, I use a selection of knives, including a good serrated knife and chill the cake well first. I also find that poundcakes, once buttercreamed and covered with fondant remain soft enough to impress finer detail of design... please view my coca cola bottle cake  and gucci bag- both done with pound cake x

www.showstoppersdecorations.co.uk

You can do a pound cake in many flavors, just by adding cocoa or other flavors.

Otherwise, make the cake you like and freeze it several hours after cooling it to room temp.  You can carve it easier that way without it crumbling apart.