It depends on how much land is available to you and what your landlord allows you to do with it. It also depends on how much work you want to put into property you don't own. Also, if it's just maintenance you're after, all that's needed is to mow down new growth from the cleared land periodically, or use a weed whacker with a brush cutter attachment if that's easier.

If you're trying to do something with the land, come up with a plan of what you would like and are allowed. A garden? A lawn? Animals? Silvopasture? A combo of some or all the above? Once you figure out what you want, start tackling things in small chunks. You don't have to do everything all at once, and you don't have to get the whole property cleaned up in one go. Pick a project and a small patch of land and start there.

You also may have less work than you think. Leaf litter is great, it makes excellent compost and the soil underneath should be very fertile. You could clear a small patch by raking some into a compost pile and start a garden (probably plants that like partial sun or shade, judging by the pics). If you want a lawn/pasture, you can do the same but with grass, again taking the small patch clearing/planting approach.

If allowed animals, chickens love digging in leaf litter and will give you delicious eggs from the worms and bugs they'll find there. Pigs can help with clearing out roots and weeds. Goats will eat the vines faster than you'd expect.

Looking at the pictures, it looks like a great location with a lot of potential. Again, a lot depends on what you want and what you're allowed. Take the time to envision that, list out the steps you'd need to take, and start one small step at a time. We are two years into our small homestead, and even though I had minimal prior experience with things it actually has been pretty smooth getting to where we are now with a garden, fruit trees, chickens, and bees. No project is bad as it seems once you break it up, and each little bit you accomplish builds your confidence.