What should i do ? Im new to this.

My brother left me his plants and i need to kno from u guys what i need to do here. Ive got one smaller plant that looks like it has bud rot maybe the sex organs are turning brown at the bottom and the leaves as u can see are also affected.
I have a bigger plant that is still in vegetative stage i believe. Theres ab 5-7 leaves on it that have black spots . I need to kno whats goin on ? I did leave plants out on a rainy day one day and im afraid it was from the moisture. Also how should i be watering the plant ? What can i give it to help it grow and be healthy ? I clipped 2 bad leaves off today and im afraid to cut anymore because it wil go into shock