At that point, you can begin trading. You can submit market or limit orders. The orders will be filled as soon as your buy/sell order can be matched to a corresponding one. Most exchanges only offer this limited structure for placing orders. However, a growing number of exchanges now allow more complex orders, including the option to go long/short on a stock and to employ leverage.
Always pay attention to Bitcoin. Most altcoins (every cryptocurrency except Bitcoin) are pegged more closely to Bitcoin than Asian currencies were to the USD during the Asian Financial Crisis. If Bitcoin price pump drastically, altcoins price can go down as people try to exit altcoins to ride the BTC profits; inversely, if Bitcoin prices dump drastically, altcoin prices can go down, too, as people exit altcoins to exchange back into fiat. The best times for altcoin growth appear when Bitcoin shows organic growth or decline, or remains stagnant in price.