There's plenty of potential shown in your sketches. The only advice is the obvious advice: just keep on drawing, try not to get frustrated and don't ever give up.
And don't get worried about hardware/software, just get whatever you can for the money you have. Like Dom, I have a bottom of the range 6x4 inch Wacom Bamboo that they don't sell anymore and it's always done everything I wanted and until recently I did everything in Photoshop Elements 5. So whatever you choose to use you will still learn and progress.
