Multiple codes including P0135, P0134

I bought this car for only $400.. I have put nearly $1,000.00 in it including what i paid for the car. I have changed fuel pump and filter, spark plugs, air intake temperature sensor, injectors and more. At first it wouldn't run i took a chance to have my very first car and halfway rebuild it from there. I have had so many codes that has been thrown at me i'm starting to think it's not my luck. As of right now my gears are not shifting, the part will be here Friday. Come to find out i changed the wrong 02 sensor with the code telling me it's too lean. I have been basically fixing all this by myself with very little help and still have more work on it before i transfer everything in my name and be road ready. Someone tell me its all worth it. That i'm not loosing my mind.

P0 codes:

P0113
P0300
P0135
P0134
P0130
P0171

Still Showing These Codes:

P0135
P0134