Step #1: Create a new folder. This will be your resource pack name.
Step #2: Create a new folder inside of that folder and call it "assets", and then inside of that folder create a new one called "minecraft"
Step #3: Go to your .minecraft folder and go into versions and click on the version that you want to make the resource pack for. 
Step #4: Search "assets" and drag the contents of that folder to your resource pack>assets>minecraft folder. These are the files required for making textures.
Step #5: Go to your .minecraft folder and find the assets>virtual>legacy folder. Go inside of that and drag all of the folders out and put them into the same folder (resource pack>assets>minecraft) then go back inside and get pack.mcmeta. Do the same with this.
Step #6: Once you have this, go into your resource pack>assets>minecraft and drag your "records" folder into your "sounds" folder. You can get rid of "sound"
Now you are all set up to start changing sounds and textures.
I reccomend Audacity to change the sounds. 
When you get a sound that you want, drag it into audacity and export it as a .ogg file.