وعليكم السلام ورحمة الله وبركاته

With regards to Ayyamul Beedh, Sheikh ibn Baz raḥimahullāh says it's permissible to fast some of the 3 days and that you'll be rewarded accordingly. https://binbaz.org.sa/fatwas/12631/%D9%85%D9%86-%D8%B5%D8%A7%D9%85-%D9%8A%D9%88%D9%85%D9%8A%D9%86-%D9%85%D9%86-%D8%A7%D9%84%D8%A7%D9%8A%D8%A7%D9%85-%D8%A7%D9%84%D8%A8%D9%8A%D8%B6-%D9%87%D9%84-%D9%8A%D9%88%D8%AC%D8%B1 🔺Note: There's days that should not be fasted individually, like Friday & Saturday, unless one fasts the day before or the day after alongside it. 💡Benefit: Abu Hurairah raḍhiyallāhu ’anhu said: “My khaleel (intimate friend i.e. The Prophet ﷺ) advised me with 3 things...one of which, to fast 3 days of every month. [Bukhāri & Muslim] Sheikh ’Uthaymīn raḥimahullāh said (paraphrasing): “You can fast any 3 days of the month, whether at the start, in the middle, or at the end of the month; whether you fast them in succession or separately. But the best 3 days in terms of fasting is to fast the 3 White days.”