Very good advice from applestar and I don't have a lot to add. But usually when you take a plant out of the pot, the roots are a bit pot bound. You need to use a fork or your fingers to gently pull them apart, so they are loosened up and hanging straight down.
What do your plants look like when they are dying? Turning yellow and wilting can be a sign of over-watering. Often people are trying too hard and tend to love their plants to death.
And absolutely second what applestar said about matching the plants to the conditions. Every plant has its own set of conditions that it needs (sun, water, soil type, etc) and either will not thrive or will die if they are not met. Stores don't usually give much if any information about that, so if you don't know you need to look them up.
What you listed is a mixed bag: I have planted ferns, vincas, succulants, umbrella tree, rose bushes
There are lots of different ferns with different requirements, but in general the common ones need dappled shade (open shade under a tall tree, not total shade, but little to no direct sun), very hummus-y organic soil that is slightly acidic, moisture retentive but well drained. Need plenty of water, but not water-logged, never wants to dry out.
schefflera (umbrella tree), I only know as a houseplant, since it is not frost tolerant. Outdoors in the right climate it can become a multi-stemmed tree 15 feet or more tall, and tending to spread. It likes bright, indirect light, not direct hot sun. It is drought tolerant, which means once it is established (has put down roots and is growing well), it does not like too much water and needs to dry out between waterings. It is not particular about the pH (acidity) of the soil as long as it isn't extreme on either end.
Rose bushes need full sun, moist well drained soil that is rich in organics, very slightly acidic.
If everything dies, you may have a problem with your soil. You should send a sample to be analyzed and they can tell you what type of soil you have (acidity, amount of organics, nutrients) and what it needs.
Hope this helps! Stay in touch with us and we will help you get that pretty yard!