I,m just an occasional visitor to this forum but most of the people on here seem to have veggies as a major interest. I think you might get more responses if you posted on the perennials forum, perhaps the rose questions on the rose forum, other shrubs on the trees and shrubs forum. I'll start with bulbs..if they're mushy they're pretty much toast, callas would not be hardy in your area. Iris should be fine, most true lily bulbs should be fine. Glads or dahlias are likely goners as well.
I'm not much of a rose person myself and trumpet vines are marginally hardy here. I wish you luck, you may want to contact your county extension service and see if a master gardener might be willing to meet with you and help answer some questions and perhaps help you id some of the plants etc.
Also, just an FYI and I mean no disrespect to your dad, I'm sure he was a terrific gardener but the term Master Gardener is one given to people who have completed training through your state's land grant university and are a branch of the university extension program. In MN they volunteer 50 hrs. the first year and 25 each year after to educating the public about horticulture. Anyway, best of luck to you and I'm sure your dad would be thrilled to know you will be caring for his plants.

Hi, CoupsN. I know you can get a lot of help on the garden forums, especially the rose forum, which is very active. Take photos to document the plants which come up as time goes by; they really help to show people what you're talking about. Get a notebook and take notes on plants, locations, etc. You're in Chicago; there should be lots of garden clubs around.

I'm sure there will also be a branch of the American Rose Society--google local chapters and you'll be able to get contact info. Someone from the society may be willing to come and look at your dad's roses and help you know what needs to be done. I would act on them quickly because it doesn't take long for roses to get out of hand or to be devastated by insects and disease.

Above all, enjoy your dad's garden. It's a wonderful inheritance. If it becomes overwhelming, consider sharing some of the plants among family members so that they can continue to live on in their gardens.
Mock orange should be pruned after it blooms, since it blooms on old wood.
The rose of sharons are pretty tough. I usually only trim mine of crossing branches and dead wood.
Hope this helps!

Take lots of pictures. People will be bale to help you more.

Unfortunately if you had bunch of semi hardy bulbs like cala lily, gladiolas, and other bulbs that do better in 7a + those kind of tropicals will not come back for you, but iris are very hardy.

I'd prune rose of sharon in early spring, as they bloom in later summer here. Trumpet vine you can let alone until late April, May when you can prune it heavily down to the base vine before it leafs out and or sends out new growth. It comes out of dormancy rather lat. It's very vigorous here in MD and responds well to pruning as it grows/flowers from new growth.

Most roses if they are repeating, you can prune it back 1/3 around now for us here in MD but I'd imagine a few weeks later, maybe closer to April for you. If they are once blooming roses, you can prune earlier about now, but not too much, 1/3 is again good maximum. If you really want to "tidy" up you can prune most once flowering shrubs immediately after their springtime bloom.

Fertilize with good composted manure if you can get it from a farm. For roses Rosetone works great.

Do you know if your father used pesticides/fungicides on his roses?

No disrespect to anyone, but, at least in Florida, "Master Gardner" is a title earned solely through volunteer hours. There is no knowledge-based examination or certification. Most master gardners are very educated in horticulture. But some are not.