I never measured any of my beer with a hydrometer when I was a newb. Just leave it alone for at least 2 weeks, maybe longer if you can. I can make an argument that one does not need to measure gravity as it's not absolutely essential at first (in my opinion). Lots of people go out and buy X, Y, and Z in the beginning when X, Y, and Z aren't as nearly as important as A, B, and C.
I know you said you really like this, so a hydrometer or refractometer would be a good investment in the future. Can't lie there as it will allow you to measure your efficiency and let you know when your beer is finished fermenting, especially bigger beers. Talk to your LHBS or read the forums/watch a YouTube video on gravity readings. However, if you give your beer time and be patient when the yeast is doing it's thing, you'll be fine without all the bells and whistles at first. Taste it and if it tastes like warm flat beer, give it another day or so just to be safe and then bottle it. Just my two cents in case you don't want to spend another $10-$15.