Diffenbachia is nicknamed dumb cane for a reason, while it is a pretty plant with many varieties, care must be taken when handling the plant. The juice is toxic and causes the inner mouth, tongue and throat membranes to swell. It’s important to wash your hands carefully after transplanting, pinching dead leaves, or dividing the plant. Children and animals need to be watched closely to avoid accidental poisoning.
The trick to getting Christmas/Thanksgiving/Easter cactus to bloom is once the plant beging to set it’s buds (tiny balls on the tips of the segments) do not change the position of it’s light source. If you do, the buds will try to follow the light, causing them to drop.
Fibrous begonias are nice, some have flowers, others have striking foliage. In my experience coleus has always been an indoor plant. It comes in a wild variety of colors, patterns and leaf types. Keep the tips pinched in order to keep them bushy, do not let them dry out. They will recover from a dry out, but they will drop a lot of leaves. Dracena comes in many types and is super easy to grow, no direct sunlight and don’t place too close to any heat source. Ivy also comes in many varieties and is nigh unto indestructible. The variagated types need direct sun in order to keep the color, and any leaves which emerge as solid need to be pinched off, but it is a hardy plant. Ficus benjamina (weeping fig) is one of my favorites, I have one I bought as a 6" baby when my daughter was due to be born, and 16 years later it is a small tree as tall as she is. Spider plants and pothos are also favorites. Persian violet is a pretty plant with small flowers resembling violets on it, pinch off spent blooms and it will continue to bloom for a very long time. I don’t have my plant book at hand and I am not remembering some scientific names, but the polka dot plant is similar to the coleus, it likes direct light, moist soil, keep it pinched to make it bushy, and it comes in white/pink/and red dots.
I also agree with all the other’s suggestions, with the disclaimer that I cannot grow orchids. My mom can, though, so it can be done!
I love my plants, inside and out, and wish you well on your future indoor jungle.