Are people upgrading their base weapons as soon as they get titanite, or waiting for something better? I've been holding on to my titanite and wondering about this. Not even at the second boss though.
Longsword is a really reliable weapon early on and even into mid-game. Attuning it with whatever works for your build is also an excellent move. I didn't drop my Fire Longsword until about 5 boss fights in, and only because I found an objectively stronger straight sword to buff up.
Also, yeah. Titanite Shards are plentiful as hell. As I'm typing this I have 33 and have used up 24.