It will work fine, no worries! You will just want to inspect it carefully for nicks in the enamel. Once you get a nick the steel underneath will rust in no time. Aluminum pots are also fine (though I don't want to start a debate, do a search and you'll see why ).
Use that pot to get your feet wet! Then, when you're comfortable with the process, buy the biggest Al or SS (doesn't matter which) pot you can find! It takes a lot of stress and mess away from Brew Day when your vessels have that extra space.