I made a mistake... I incorrectly thought the "download manager" apk was a worthless Virgin Mobile stock one, so I deleted it. Well, I'm a bit wiser now, and I now know that the Google play store requires it. My question is this: is there a place where I can download the apk?
I dont think that the play store requires a download manager. However if you want to download something from a browser es explorer can provide you a download manager. So download es explorer from play store. Its a great app with tons of functionalities.
The download manager apk is different for each device as it gets compiled during the final build. I suggest you reinstall your firmware if your device manufacturer allows something like that.
You can find other expert users on here or xda who use the exactly same device you use but rooted. So they can extract that apk via titanium or root explorer and give it to you, so you can push it again in your device with root explorer.