Congrats! Thick leather gloves are fantastic for thorns, so that's what I would recommend. I'm a glutton for punishment, though, and when I don't have my leather gloves I'll still dig through thorny plants, albeit veeeery gently. That's normally if I'm just pruning small patches of blackberry or roses, though and also I'm a masochist lol.

If a ton of the thorny plants are blackberry, it might be a good idea to hire someone to clear it. I've never done so but they are voracious growers. You may know this, but any branch that touches the ground can put off new roots and grow even more and so on. Unless you can dig out all of the roots, just going through and cutting is a losing game, unless you get it cut back to where it's manageable and you don't mind pruning regularly.

As for garden clippings, composting is the way. You do want to make sure that you aren't getting any weeds in your compost, though, otherwise they will profilerate and your compost soil will just spread more weeds. Again, you may know this, but for browns, save any unbleached paper that you can. Torn up cardboard, newspaper, napkins,coffee filters, paper grocery bags, chopped up twigs/wood chips/shavings, dryer Lint. If you can shred your brown foliage that's great as well. If there is a farm/feed store somewhat close to you, you can buy straw for fairly cheap and that will last forever depending on the size of the compost pile.

Also, if you can look into native flowers for your area and scatter a ton of seed once you've cleared out weeds, they can help to eventually keep the weed population under control. Clover helps with this, too and can be good ground cover. Just wanna make sure it's not invasive in your area and it doesn't choke out your natives