-leaves are yellow and dry - dry leaves seem to be around the bottom - the plant seems to be supported with a small trellis - is it an indoor plant or outdoor plant
I think you are referring to a mandevilla plant, which is a tropical vine for indoors or out. These articles should help with its care:
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/winterizing-mandevillas.htm
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/yellow-leaves-on-mandevilla.htm
but what if the bulbs split open.
Since there is only one, I suggest wearing gloves and pulling it. Place in a bag and dispose. You could even spray an herbicide into the bag before disposing of the bag.
https://www.gardeningknowhow.com/plant-problems/weeds/jimsonweed-control.htm
I have two shoots growing in container pots and I want them to be inside to provide better air than my closed up apartment has now. Also, are they toxic to guinea pigs if eaten?
All parts of Datura are toxic if consumed. Convulsions and coma can result if enough is eaten. I would not let pets or children anywhere near it.
Here's an article to help: https://www.gardeningknowhow.com/ornamental/flowers/datura/moonflower-vs-datura.htm
https://plants.ces.ncsu.edu/plants/datura-wrightii/