To answer the OP’s question 2 in more depth, any of the charities recommended there would be excellent candidates: GiveDirectly and the two deworming charities (which you pick will depend on which is tax-deductible in your country). GiveDirectly is certain transparent and efficient, in that it simply gives a large unconditional cash transfer to poor families, with around 90% ‘efficiency’ in the sense that 90% of your money ends up in their pocket. See this accessible introduction and this detailed analysis.
To answer the OP’s question 2 in more depth, any of the charities recommended there would be excellent candidates: GiveDirectly and the two deworming charities (which you pick will depend on which is tax-deductible in your country). GiveDirectly is certain transparent and efficient, in that it simply gives a large unconditional cash transfer to poor families, with around 90% ‘efficiency’ in the sense that 90% of your money ends up in their pocket. See this accessible introduction and this detailed analysis.