NWR: Xmas ornaments?

So this is the first X-mas that FH and I are having together in our own place and we just realized, we don't have x-mas ornaments! I have a few hand me downs but not nearly enough to cover an entire tree.

Uhhhh....where is the best place to buy ornaments and how many would we need?

I bought pretty glitter ones at Target

Also, they can be expenisve but Hallmark has nice ones.

As for how many I'm not sure we add more each year