Welcome to Tug. Have a seat and keep reading. There are many people here who can provide specific information about your options. But in general:
You can't get out of a timeshare purchase that isn't paid off. Until the deed is free and clear, even the "get out of your timeshare" companies won't be of any help.
Those "get out of your timeshare" companies are generally a scam. They charge you a big fee up front, then just list your timeshare for sale on a website nobody reads. Your listing is surrounded by dozens of other identical ads, and nobody wants to buy a timeshare with an outstanding mortgage. The company has no interest or incentive in actually selling your timeshare, because you already paid them. And when the maintenance fees come due again, they're still your responsibility.
Figure that the resale value of what you own is zero. Check eBay for Completed Auctions to get an idea of what things are actually selling for. As a buyer, it's nearly always best to buy on the resale market.
There is no difference between "new" and "used" in timesharing, except for the price. Even if you bought a new timeshare still under construction, by the time you get there to use your time, someone else has already slept in that bed. After you're an owner, the ongoing fees you pay as a "new" purchaser are the same as someone who bought "used" on the resale market.
The seller is unlikely to take it back, since their interest is in selling them, not buying them. If you owe money on the purchase, then double-down on this reality. You're pretty much stuck with what you purchased, sad to say.
Bonus Weeks are a standard in the industry, and it's ALL leftovers within a short timeframe to check in. You can't generally schedule them months in advance. If they were available then, they wouldn't be considered a Bonus. By the time you factor in costs and assorted add-on fees, they are rarely a good deal unless they fall directly in line with your exact needs. Consider them a found option, good to use once in awhile, but not something to count on.
Your best option at this point is to learn how best to schedule and use what you own, and make the most from it. Many Tuggers were in the same place you are - they didn't learn about the Resale market until after they'd purchased at big bucks from the Developer.
Sorry to be the bearer of bad news, but the above is pretty much your reality right now. After the pandemic is over and things open up, you'll have the ability to use what you bought. Till then, hunker down, read Tug, and learn all you can about how to make the most of your purchase.
Good luck,
Dave