You have listed several questions which would require more space than that allowed in this forum so I encourage you to google CA Cooperative Extension Service. They will provide you with numerous booklets which will guide you toward your goal. Good luck.

Welcome to the wonderful world of gardening!

You have a lot on your plate and I would recommend separating them out.
1. Clean out the spot to garden
2. Test the soil and see what you have to work with
3. Figure out what you want to plant
4. Stop the cat from using the area as his/her litterbox

Since you are a new gardener, I would not recommend using the entire space but slowly growing into the space year by year. This will help you learn as you go along and not get discouraged.

1. Cleaning out the spot - I'm not sure what equipment you currently have. I would invest in a good pair of gloves, a shovel, pruners, to start with. You'll want to cut back/mow down as much as you can and dig out the young trees (if possible). If the young trees are too established, you can cut them down - use your best judgment on this. I'd leave the bushes for now as you may be able to prune them back to where you want them.

2. Test the soil (your local cooperative should be able to do this). Get a sense of what you're working with. Do you have access to a horse or cow farm? You may want to spend the first year just amending the soil and getting it ready to use. Another option is to build a small raised bed and put soil, manure, etc. in there. Are you composting yet? If not, consider putting in a compost bed for vegetables and other non-meat scraps to be used later to enrich your soil.

3. Deciding what to grow there is more difficult. You're in a completely different climate than I am (I'm in NY). Once you cut back the trees, etc. will you still not be getting any sun? How much sun does that area get? Your cooperative extension is a good place to start and get some ideas. Also visit your local library and look for books specific to your area -- there is nothing as disheartening than planting and finding out that none of your plants are hardy for your area.

The fun thing is that you can start doing this while you're cleaning out the area.

4. I have no ideas for the cat. You could ask your local vet if they have any ideas but it's hard to control an outdoor cat doing things outdoor.

Good luck and keep us posted on your progress! It's so excited that you have a beautiful clean slate to work on and so many possibilities of what to do with it.

-Rini

Hot pepper spray repels cats:

Get the hottest pepper you can find,
put it into a pot of water & bring it to a boil.
Remove from heat & allow to cool.
Strain the peppers out of the liquid & chill the liquid overnight.
Put the liquid into a spray bottle, & spray the *area* & the *plants* with it.

You'll need to re-apply the spray periodically, as it does wear off.

Keep the unused mixture in the fridge.

Don't use this or any other concoction on an animal, as so many mixtures will blind the animal or cause lung damage or great pain.

If you happen to see the cat in the area, you can spray him with plain water in a spritzer bottle.

Best luck, & have fun!