Firstly, you haven’t messed anything up! It’s still very early days and you’re at the best time to be able to encourage new habits. Your puppy will flourish by being loved - you just have to enforce some boundaries.
Until she can be trusted not to mess on the carpet, or cause havoc, she needs to be confined to a space where it’s easily cleanable, easily puppy proofed, and easily monitored. I worked from home for the first few weeks(months!) when I first brought our pup home, that way I knew what she was up to almost all the time, and could keep my eyes out for toilet cues. As much as that worked during the working day, it meant that I spent a lot of dull evenings at the kitchen table! Can you set up a playpen in the living room you can keep her in? That way she’ll still be part of family life but cannot cause as much destruction and you can pop to the toilet without worrying what you’ll come back to. If you want to use puppy pads, do. I did with my first two pups and they both ‘got’ toilet training fairly easily.
Crate training was a game changer this time around - had never used one before but also had never had a puppy and small children before. We no longer use the crate (she’s a big dog and it just took up too much room ultimately) but for the first 9 months, she was in the crate all night and whenever she was left home alone. Dogs don’t, typically, soil where they sleep, so crates really help with toilet training. They aren’t for everyone, but I would suggest giving it a try, especially if you know anyone with one you can borrow, or get cheaply from Facebook marketplace etc. Make sure it’s big enough for her to be able to get comfortable in, but not big enough for her to have too much room to wander around. Don’t expect her to love it immediately - but introduce it slowly, and make it somewhere she wants to be. What is she driven by? Treats, toys? Use them to encourage her to go in the crate throughout the day. Don’t close the door at first, just let her get used to it. Some people feed their dogs in the crate (I never did but it is suggested on lots of threads). If you want her in it overnight, you may need to help her settle - our crate was too big for our bedroom so I slept downstairs until she was happy with it. It took ‘shhhhh’ing, stroking through the bars, and persistence, but it didn’t take long for her to know that was the place for sleep.
Does she get plenty of sleep during the day? What mental stimulation does she get? Puppies are more destructive (and bitey!) if they are tired and/or bored. Make sure she has plenty of naps, and plenty to keep her brain ticking over - I used to use 50% of the daily food for sniffy games/treats/training and never fed from a ‘normal’ dog bowl until we went on to raw food. The kong wobble feeders are good to keep them occupied and stimulated if you’re feeding kibble, or when the weather is better you can scatter feed (throw the biscuits around the garden for them to sniff out their dinner)
The thing is with puppies, it doesn’t matter how much you have read up, how prepared you are, or even how many puppies you’ve had before - they can still be completely overwhelming at first. But as long as you’re willing to put the time and effort in, things will start to get better, and before you know it you’ll have a fully matured dog that you couldn’t imagine living without.