Hello, welcome! I joined here a few months ago while I was watching S2 for the first time. Being a member here on my first viewing was joyful for me, hope you will have fun, too!
Be careful about spoilers though, I suggest staying away from Inside Out and Cast&Characters forums until you get to the S7 at least. 😄 You can check forums for each season as you watch the series, there are episode-specific discussion threads. There are also off-topic forums, and fanart, fanfic forums if you are interested. 😊
Welcome to the forum! There are season episode threads which can usually avoid spoilers but the best way to do that is watch faster! The discussions here are intelligent and civil which is not always (or usually) the case with fan forums.
Angel is another good show that is in some ways better than Buffy but in some ways uses ideas and plot points that are too outrageous for Buffy.