You may watch Angel after Buffy, as Angel overall functions as its own show. However, there are some events from Buffy that explain or lead into occurrences on Angel and vice versa. These occurrences mostly happen during Buffy seasons 4 and 7/Angel seasons 1 and 4. Also, some events from Buffy's series finale carry into Angel season 5. If you are confused about certain events or need to know how/when the shows crossover, the Fandom guide for the episodes could help. Since you are within the last two (televised) seasons of Buffy, I would enjoy them and then watch Angel.
