You are trying to learn and I don't want to discourage that so here are some tips.
Only buy .com. Anything not a .com has a less value and in most cases has no value. Unless you can get something like love.cc, not going to make a mint in anything that isn't .com.
The reseller market is all about buying low and as such anything you get will have a much lower value sold to a reseller however you can still buy low and sell high! Find a domain that has some value, develop it and make bank. Then repeat.
Some value means ....
Less than 10 characters.
No dashes or digits. (ie: I-Love4U)
The domain should have no more than 3 words but two is preference. (ie: LoveYou.com or ILoveYou.com)
Use real words that have real meaning to some sort of content. Because the name of the domain must fit what the theme of the site is. For example, iDream.cc. What does it mean to iDream?
Once you get a domain, build a small text heavy site around it. Get it indexed in all the search engines and trade hard links. Get the site relevant traffic and this may take some time and while you wait for the search engines to do their thing be working on site two and then site three and four and five.