Raspberries are good place to start as they are fairly easy, yet rewarding. If only 2 plants plant them at 3 feet apart.
You can go as close as two feet, I did this as i had a lot of plants. But they are really crowded now. Don't expect any fruit this year, although a few berries may form on the canes you plant. It will grow branches and new canes should also come from the crown. They will fruit in the 2nd year. Remove canes that fruit. Don't fetilize till you see growth. Every year I add compost and organic fertilizer on top, then mulch lightly. I use pine straw.
Any questions just ask.

You don't include your zone in your name portion of the post. You should include that. I am also in MN, about 25 miles north of Brainerd. Black raspberries are not easy to grow where I'm at. The one that I tried was the Pequot variety. It really struggles with our winters.

My best raspberry by far has been Boyne. A red variety. a really trooper at handling MN winters and produces lots of excellent flavored berries.

Do you know anyone in you area that is doing OK with the black raspberries?

i don't live that far north, more of in the twin cities area. The winters are harsh but not at harsh as in bamidji/brainard.

You're going to need a trellis, or some way to support plants. Here's info on raspberries from the University of MN, since you're there, best see what they say.

Here is a link that might be useful: UM extenstion services

Okay..... thanks for the tip..... will do. when do you guys think I should transplant the wildflowers? the nurshery says as soon as possible but with all this crazy weather we've been having I don't know.

Best to transplant when dormant, but yeah the ground needs to be workable. They may not respond well this year. Fall seems to be a better time, for perennials, but spring is OK for some.
If you don't have luck with these raspberries, you might want to try the new primocane fruiting Niwot black raspberry. It's new, and Nourse Farms will be offering next year. It is supposed to be hardy to zone 5, but they still are being tested. Offered this year from Henry Fields at a crazy high price. Anyway don't give up if you fail, try some hardy reds, many in the MN document were listed as excellent for your area. I'm in zone 6a/5b and find almost all work here. Even this cold winter, the canes look good. I don't think any died.

Okay. i transplanted some of them.( the wildflowers this afternoon) Will wait on the others

My raspberries might as well be weeds here (zone 8) and seem to do fine in my clay soil. If you are impatient, you might look for second year plants, or if you can do fall bearing, they will fruit their first year (and it's so nice to have berries in September and October, although they aren't as prolific). I have several different types in my bed, growing berries is very easy here. I
Since you are growing against a wall, you are fine to just twine them back this year. We have a pretty basic system with some wood posts.