I'm gonna copy/paste your questions and go through my experience with each topic. I'm not bunny expert, but I can at least offer my experiences from my first two buns to the three rescues I've got now.
1. how do i litter train her
I didn't even realize I could litter train my first two until like.. almost two years after the fact. I was eighteen or nineteen, and we only ever had a pet dog. I was literally learning as I go. Spayed/Neutered buns are definitely easier to litter train. I lucked out with my first two. My male never sprayed or peed outside of his cage. My female had bladder issues after a major health scare after a couple months, but she always gave me a cue to go off of that let me know she had to go. The buns I have now, aside from one, are fixed. Luke was horrific; he was a sprayer, peed wherever he wanted, and more or less refused his litter pan. (He always was found as a stray and had been on the streets for who knows how long.) Once I got him neutered, it was a world of difference. You may be best off getting your bun spayed/neutered. My first two buns seemed to be a bit of an exception.
2. i was looking to harness train her? So that i could bring her outside with me in the summer. Not on walks but just so she could be with me while i read/tan/garden. I already have an out door run thing but shes small enough to get through the holes for now.
In my novice bunny owner days, I got a harness without looking into any risks. I figured it was safe if it was offered on pet store shelves. (Please dig around on here to see what ones are considered safe.) I slowly introduced my male, Caramel, to the harness I had gotten. I checked the fit, let him wander my room with just the harness on, and eventually took him outside. He was frozen and hardly moving for about an hour before he started to explore and check things out. One of the only times he ever went fearless-mode, he went to bolt. The leash for the harness was a 'stroller' leash, and when he reached the end of its stretch, it flung him back at me. I was a panicked mess. I never used it again. Pretty sure I threw it out the second I got back in the house.
So the bunny run may be the best bet once your bun is big enough to not slip out or escape. Just make sure to take your time with introducing new things. My first two buns were heavily bonded with me before I started to do introduce all sorts of things to them. The only thing I put a focus on was getting them comfortable with the car. Caramel used to sprawl out and flop on my passenger seat outside of his carrier, to the point I actually did do away with a carrier for him and my female, Chocolat. (I do *not* recommend doing this, in hindsight. They ended up with carriers at the vet's request, for their safety in the lobby.) The three buns I have now all have carriers, because I got them well past their baby days- and I am not their first owners.
3. Can i teach her to come when called? Or any tricks
Seriously, YouTube videos on this. My dutch, Luke, does respond to his name. He will stand up on his hind legs for treats. My lionhead, Harriett, is just a wee old lady and I won't try to teach her tricks. She's most content with endless chew toys to destroy seemingly overnight. And my dear lop, Sweet Pea, is about playing hide and seek with my dog. I've seen videos of the tricks people have taught their rabbits a series of tricks. It is astounding, but I'm sure it takes time and patience.
4. How do i pick her up without scaring her?
Most rabbits do not like being picked up, and they will fight you on it. I refer to myself as having been stupid lucky. I had fellow bunny owners on my Facebook telling me their bun would never let them pick them up or hold them the way I could hold my Chocolat. Caramel, however, was hardly comfortable being held. If I was sitting down on the couch, he'd be more content with perching himself on my shoulder, if only because the back of the couch was right there to escape to. He was more run by anxiety 24/7 whereas Chocolat was just all about cuddles and being cradled. I couldn't do any of that with Sweet Pea, Luke, or Harriett. Harriett, when held, will snuggle into the crook of your arm to be comfortable. Luke wants to be picked up, have you rub your nose against his, give head pets and smooches. He's the mush. Sweet Pea doesn't particularly care for being picked up these days; it has to be on her terms. Every bunny is different though, but don't force it on the bun... And certainly do not be upset if they don't ever want to be picked up. I would get bummed out over Sweet Pea not letting me pick her up, because I was spoiled by my first two rabbits- who both seemed to be exceptions to a lot of the bunny rules. lol.
Just know they'll come around over time as you bond. Eventually, your bun will approach you and maybe even come onto your lap for pets. Some buns are easy to bond with while others take more time. It depends on their personality. Caramel was a permanent ball of anxiety, but he could still associate safety with me, or even my father whom he bonded with later in his life. Whereas, Sweet Pea couldn't care less about anything, but if she spots you while running loose, she will approach and bop you with her head saying she wants your attention and pets.
But you've definitely got plenty of people willing to guide you when you need it and answer any questions you have here. ;] I'm sure some of the folks on here may cringe at some of my earlier experiences and own doings with my first two buns, but I've learned a lot since then and cringe at some of it myself. :embarrassed: