Is the rabbit you are getting already fixed? If so, she should take to a litter box almost immediately provided you have a good setup. Based on what you are showing in the photos, the following would be my suggestions....
1. remove the water bottle (it's hanging too low anyway) and just use the bowl. The bowl you have is a bit small -- half the size I'd suggest.. I would suggest getting a 20 oz capacity bowl.
2. Do not use puppy pads in the bottom of the cage while litter training. Any place soft is where they like to potty. So during training, the only "soft" place should be the litter box.
3. I agree that the litter box is too small. Corner ones just make litter training more difficult. If you want to litter train in the easiest way, get a larger rectangular or square box. Any plastic box will do. It doesn't have to be an "official" litter box. Check here for proper litter box setup:
https://rabbitsindoors.weebly.com/litter-training.html
4. The hay should go on top of your litter inside the litter box for easiest litter training. You'll add fresh hay on top a couple times per day. The hay racks that come with those cages are pretty useless as the primary way to feed hay. They are ok for nibbles of hay.
5. Free roaming. The others are correct who said that it isn't wise to allow free roam right away. That often results in potty accidents that are very difficult to un-train! The first 48 hours, bunny should be left
completely undisturbed in her cage. You can talk to her, but no reaching into the cage to touch her or pet her. Two important links here: one for what to do the day you bring bunny home and the other on how to free-roam.
https://rabbitsindoors.weebly.com/bringing-your-rabbit-home.htmlhttps://rabbitsindoors.weebly.com/free-roaming-how-to.html
5. Toys. The woven grass mat is a great option! The smaller plastic cat balls tend to be very thin plastic. Bunny may chew and ingest the plastic
Any plastic toys should be real thick plastic. So I wouldn't use the thin plastic balls. The cylinder-shaped ones may be thicker. The cat wand is a no-no. The string and feathers are both dangerous for bunnies. Don't use it. This also applies to the the string and ball attached to the tunnel. Cut that off. Don't use any of the toys with feathers. There also appears to be a crinkly foil type ball -- avoid that.
6. I'd still suggest getting an exercise pen. This is most helpful
during bonding time. It's also helpful when you want bunny to have some
exercise but can't watch her closely. You'll also need an ex-pen when you
begin to free-roam because free-roaming needs to be done in stages (as the link above explains). When you begin to bond with her (after that 48 hours!), it is very important that you
do not reach into the cage and pull her out. You'll use the exercise pen to create a space around her cage and open the cage door. Then you may sit inside the exercise pen and wait for her to come out if and when she feels ready. You can read more detail on this here:
https://rabbitsindoors.weebly.com/bonding-with-your-bunny.html
7. As for exercise, rabbits exercise (binky and dash about) in areas they are comfortable. That's best done in the safety of indoors. Outside can be scary and intimidating for many (not all) rabbits. I would not be taking any new rabbit outside until you've had them for months and are fully bonded with them. Then, if they do go out, it's best in a run or enclosed pen. Harnesses can be quite dangerous and pose many risks. But most important, right now the House Rabbit Society is saying to not let any rabbit outdoors because of the outbreak of RHVD2 in the US. There's a
separate link on this forum about that.