I'll answer the slightly broader question "How should I plan my first backpacking trip in Oregon or California?" (with emphasis on California, since that is the area I know best)
Since you are mentioning fishing and hunting, I am going to lead with permits.
- Make sure that fishing and hunting is permitted in the areas you are considering. Hunting is not permitted in any National Park I have been to. The park service and land management agencies for the Sierras are trying to get rid of non-native trout in the region because they threaten an endangered native frog species, so if you are looking to fish that is a good area, you need a license though. Keep in mind that the best lakes for fishing might not be appropriate locations for your fist trip, since they are more difficult to get to, so don't rely on fishing for sustenance. I know a ranger for the Inyo Mountains who tries to subsist mostly off of trout and brings rice and dried fruits to supplement. That seems to work pretty well if you are an expert fly-fisher.
- California's backcountry wilderness is suffering from heavy use. Many areas require overnight permits. You can apply for those online or you can gamble and show up in person. Some areas are notoriously difficult to get permits for, especially regions that include Mt Whitney, the John Muir Trail and the PCT.
- To apply for permits you will have to find out what agency has jurisdiction. This might be the US Forrest Service for National Forests, or the National Park System. As a general guide, the forrest service is more permissive when it comes to what kinds of use are allowed, but please inform yourself beforehand if in doubt.
When acquiring an overnight permit, you will have to sign that you will adhere to the principles of Leave No Trace, and rangers patrol the area for enforcement. Since this is your first trip to the backcountry, please make sure you familiarize yourself with those, to make sure that people who come after you find the place just like it was before. Depending on the agency in charge, additional restrictions or guidelines might be in place. Many of the highly traveled locations have restrictions on how to deal with humans waste that might be surprising to the uninitiated, so please make sure you are willing to follow those rules before you decide to backpack in an area. I think a good way to think about backpacking in our protected wilderness areas is to see it as a privilege that comes with responsibilities, not a right.
Another thing to consider when choosing a good spot for your first backpacking trip is the availability of water.
- When backpacking in mountainous regions, you can often plan you trip around water sources which is very convenient because you don't have to carry your entire supply with you. I would suggest you purchase a water filter if you are planning to drink water you find. Running water is best, lakes are fine, puddles are not (avoid stagnant water).
- When backpacking in regions without readily available water sources, for example deserts, make sure you know how much water you will need for the entire trip. Here is another question that might help with that.
Make sure you have a good map of the area, and make sure you know how to read it. Tom Harrison Maps are ubiquitous in outdoor stores and visitor centers in California. Those are great maps for beginners. They have the main trails marked, and unless I am going cross country, I find them more convenient than USGS Quadrangles. Purchasing a map might actually be a good first or second step in planning your trip. If you do this at a visitor center, they might be able to help you with great advice for where to set up camp along the way.
Distance and Elevation:
- As a beginner I suggest daily goals of not much more than 5 miles, especially when in mountainous terrain. Carrying a heavy pack will be unfamiliar, and it is good to slowly gain elevation over a couple of days to avoid altitude sickness.
- Topographical maps are great for figuring out how much elevation a trail gains. Google Earth is also great.
Here are a couple of asides:
- Your hope to avoid people altogether will be difficult in California, since especially during summertime people swarm to the nice backpacking locations. You can avoid people by planning cross-country trips, but that is not an ideal first trip. Make sure you have a couple of years of experience before planing anything like that.
- The area you are interested in is bear country. Don't leave any food in your car. Many trail heads have bear lockers where you can leave anything a bear could be interested in while you are on the trail.
- Speaking of bear-country: Some areas require that you carry your food inside a bear can. You can rent those at the visitor centers where you will be picking up your permit, or you can buy one. They are clunky and heavy, but make great chairs! Hanging food might still be allowed (depends on area) but I don't advise it in heavily traveled areas, because it damages trees.
- Don't go alone, especially if this is your first trip.
- Make sure you resist the temptation of bringing stuff you won't need or don't know how to use. I have lead several backpacking trips for beginners and every single time participants mentioned after the trip they wish they had brought less stuff.
- Buy or rent appropriate equipment (don't bring cotton, select appropriate sleeping bag...), know how to pack your pack properly and bring a stove for areas that don't allow collecting of firewood (many places in the Sierra Nevada).
- Make sure you are appropriately protected against the sun. Hat and sunscreen are not optional.