Hey, Welcome to CC!
Don't worry about not having too many bricks, you can still build great vignettes while you build up your collection. And Fancy Bases are just that, Fancy! Much more important is the build itself; and this one is great! There is real potential here, I love how you positioned the figs and created that rubble. In terms of helpful criticism, try adding some green plates for height variation on the grass as well as some rocks and trees. Maybe even expand the base and add a small stream. Nothing sets off an awesome castle like pretty landscape.
Now if you are looking to Improve your skills, check out the Tutorials Page
. It is chock full of great techniques and ideas for you to try. This one
by Derfal Cadarn has been a recent inspiration to the entire community.
For building up your collection, try Bricklink.com. It is A great website with a vast selection of indivudual parts/sets.minifigures for very low prices. But be warned, many of us here call it cracklink since it is so addictive
. Lastly, don't ever get discouraged, only inspired; There will always be people with more bricks and skills then you, so just have fun trying to be the best you can be!