you can do this hike! it’s long and the grade is kinda steep in some places but super worth it (there are also gondolas that can take you up in some spots, but you won’t get the same magnificence).
I did alta via 2 a few years back and it’s one of the most fun and rewarding things I’ve ever done. part of the route we took was a 4 hour, cable-assisted, vertical climb (“via ferrata”). that sounds insane but honestly it was one of the least difficult (but most fun) parts — if you have some experience climbing in a gym you’ll find it easy (the gym is actually harder because free climbing is, well, freer, despite the route being much much longer). but that’s completely optional.
along the path we stayed in, for lack of a better term, mountain hostels to stay the night. they serve the most amazing food you’ll ever eat because you have worked fucking HARD for it.
i’m sure they offer guided hikes but we planned the trek ourselves with a guide by Gillian Price — we even found this location and took a cool photo to match the cover up to the actual range :)
all in all, hard yes; do recommend. any outdoors person should look into doing this awesome and gorgeous trek!
I highly recommend getting this book: Trekking the Dolomites: Alta Via 1 and Alta Via 2… The Alta Via 1 is considered the less technical trail than Alta Via 2. I’m not entirely familiar with each section and what would fit best for your itinerary but hopefully this book will give you a decent idea of the trail itself.
I did two weeks in the Dolomites back in 2015 and it's one of my favorite places on earth. It's extremely beautiful and very affordable compared to some parts of the Alps (I'm looking at you Switzerland!).
If you're going to do a lot of backpacking in Europe, get yourself familiar with the Cicerone Brand guidebooks. They are the absolute best. Here is the one you'd need for the Alta Via 1 or Alta Via 2 (https://www.amazon.com/Trekking-Dolomites-Routes-Outline-Cicerone/dp/1852848200/ref=sr_1_1?ie=UTF8&qid=1547258082&sr=8-1&keywords=cicerone+dolomites) My wife and I backpack over there (Europe) once a year, and after we pick an area, the first thing we do is buy the Cicerone guide. We have a whole library now.
That being said, I did the Alta Via 2. The Alta Via 1 is by far the most popular. The Alta Via 2 is longer, less crowded, but a touch harder. The Alta Via 1 you'll definitely need to book ahead for the mountain huts. When I did the Av2, I did it in early September and never made a single reservation ahead of time and never had issues finding a place in the Huts.
Before you go, sign up for the Austrian Alpine Club, UK chapter (https://aacuk.org.uk/). It gets you discounts at all the huts. Usually it was $20 a night per person in the huts, I think it was $11 with the card. It also includes rescue insurance so you don't get a helicopter bill if something goes south... Food was about $8-12 per plate for dinner or lunch, and all the huts have beer and wine as well, and it was affordable. I found the food to be quite nice.
Let me know if you have any other questions. My wife and I live for backpacking so we've quite a bit of experience.
Good luck!
TLDR: Buy Cicerone Guide, do the Alta Via 2, join AACUK