How can I find a fun way to develop muscle?

A lifestyle change requires you to get out of your comfort zone in many aspects. For cardio there are several ways you can make it fun, but for strength training? Not sure I can think of any that doesn't involve dangerous or crazy activities (wrestling bears?)

I enjoy weight lifting a lot! If you don't, try to convince yourself that you do, like the saying that goes "fake it til you make it." Eventually I'm sure you are going to enjoy it from the results you get.

By the way, if you are eating at a deficit you won't build muscle, but by lifting and eating at a deficit you will maintain your muscle (make sure you eat enough protein too) and lose fat, which will give you that "toned" look.

I'm surprised by this, because it has never been my experience. It's sort of like a video game - sometimes you have to do some grinding, but leveling up (or lifting heavier weights) is worth it!

Maybe you would have more fun doing body weight exercises. You won't be picking things up and putting them down, and it'll be based in wielding your own body, climbing, pushing, real life motions that are clearly things you're going to use. You can check out You Are Your Own Gym if you're interested in doing something like that.

Sometimes we have to do things we don't necessarily want to do in order to get what we ultimately want. I'm more than sure that if you dedicated enough time and energy to a solid weight training regimen you would see some fantastic results in a fairly short amount of time. Those results would make you love weight training. I've never ever met a person that is toned and or muscular that didn't fall in love with weight training after a while.

With that said, you have to want it bad enough to just do it. "It's boring" really just means you don't want it bad enough.

maybe stop looking for entertainment and start looking for progress instead?

i can't speak for everyone, but when i'm setting up goals and steady knocking em down that's all the fun in the world

There are activities I find fun that get me moving and toned, but that take the "work" out of working out. Stand Up Paddle Boarding and Rock Climbing (even at those indoor, wonky fake rock gyms) are both incredible workouts, board sports of any kind for balance and core engaging activity and wow- you should've seen my back, arms, and shoulders the summer I took Rock Climbing at my community College! Dance is actually pretty toning, too. Bellydance and Flamenco have a lot of arm posing and movement depending on the styling, and some people claim yoga and Pilates alone were enough to get some serious toning using only one's own body weight. I don't think anyone is obligated to workout (or be healthy, for that matter), and I think moving can be seriously fun. Bodies are meant to move. I recently found a parkour gym in my area, so I'm pretty certain I'll get a good workout trying that out and seeing if I enjoy it.

Don't feel obligated to push through a workout you don't enjoy. Life is short and you won't stick with it if you truly don't like what you do.

I echo any type of paddling for upper body workouts. I'm just back from my first canoe paddle of the year. Stand up paddlingand kayaking are also great. If you want to up the intensity try Dragon boat racing or out rigger canoes.
Not only good workouts but also fun times!

Yes. Dragons boats ftw. So, so good! Swimming is pretty all-around toning, too, but OP seems to get bored so easily that I think she'd need something more interesting than just laps. If you're daring, most martial arts forms are pretty good at keeping classes interesting and you'll definitely feel your muscles when you're beating up crash pads with explosive energy. Or you could try a Barre/Ballet fusion class, if that's something you're into. It's got cardio, toning, and stretch all in one go, so it's pretty effective, and I personally enjoy their classroom environment.