If you can get 1/2 inch PVC tubing in 20 foot lengths, you can make a hoop over a 4 foot wide bed that's roughly eight feet high in the center. Shove four rods of rebar thin enough to go inside the tubing and long enough to get a firm hammering into the ground with a foot or so sticking up. A couple of bent nails or electrical conduit 2-hole clamps can help with steadiness by "attaching" the rebar to raised bed sides if necessary. Slide the tubing down over the rebar. Don't worry about roots.

You can put up hoops in parallel like a Conestoga wagon or cross them in an X. You can also put up plastic tubing "poles", which means straight sections that don't hoop back down; they will be more flexible.

How's your wind, and are you comfortable putting large sails into the wind?

I was given a hot tip for edged and grommeted shade cloth: Harbor Freight. They also have scads of cheap clamps or you could use those huge binder clips!

Also remember, you don't have to shade all the plants if some are in the shade of others.

Here is a link that might be useful: Harbor Freight

IMO, I would use no higher than 30% shade for your veggies. I only used that shade cloth for houseplants. Is there anyone in your area doing the same thing you can ask? Or maybe ask at your local ag center?

You can make hoops easy and cheap with 10 foot 1/2 inch EMT conduit. Bend it with your foot. It is very easy.
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Here I am making a tunnel for 14 foot greenhouse film. I couldn't get the EMT in the soil there very well so the project was put on hold. I will obviously connect the 2 pieces once they are pushed in well.

As for shade cloth, the proper greenhouse kind is super expensive and since you need so little try the shade tarps at home stores. I also use the cheapest grade of weed blocker as a shade strip in summer, but not up in the air.
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Thanks so much for your replies! I'll take the advice about the 30% cloth and shopping at Harbor Freight. Too bad I just threw away a mailer with a good coupon from them. People around here do a lot of moving bedsheets back and forth on the hottest days/parts of the day and I didn't want to mess with that. Many people are also just generally better/more experienced at gardening and somehow get tomatoes to keep going in 100 degree weather. Thanks for telling me what measurements of hoops I need. This is my second vegetable garden ever, and I hope it goes better than my first.