Trichlor is just a type of chlorine that has cya in it. Since your cya is only 30, you can use the trichlor after you get the pool clear. But, you'll need to monitor your cya reading and when it gets to 50, stick with only bleach. Trichlor isn't used for shocking which is what you are being advised to do for now. So just use bleach now.

10% sodium hypochlorite is just strong bleach. Household bleach is 6%. However, if it has been sitting for awhile, it isn't going to be full strength. You can go ahead and use it however. Just make sure it doesn't list any other stuff besides sodium hypo. It may not raise your chlorine level significantly if it is really old and weak, but it won't hurt to use it up.