Liquid oxidizer: there is very little choice, especially among liquids that don't kill you just by reading their safety data sheet. Over time, it has boiled down to 3:
- Liquid oxygen, the one with good performance. Cold, with associated worries. And it makes some silly jokes, like burning the metal parts if it's hot, far more so the polymer joints.
- Nitrogen tetroxide, which is toxic. Manageable in gram quantity, big worry by the ton.
- Hydrogen peroxide, which detonates without easily foreseen reasons.
Then you have older choices like concentrated nitric acid, which have no clear advantage over tetroxide. Many users try to get better solutions but don't; it's a current research topic, knowing that the answers will have low performance.
For your fuel, if you want performance, no oxygen atom should already bind to a carbon or hydrogen. An alcohol is a bad choice. A nitro-something is less bad for performance, but pure nitromethane was abandoned for rockets because boom. As you need a separate oxidizer, a good fuel is a hydrocarbon, like kerosene.
The next big deal in liquid launchers is oxygen-methane. If you choose oxygen, methane adds little complexity, and makes a few things easier than storable liquids.
You should look how you will cool the combustion chamber's wall. Usually done by circulating the fuel in channels, and this puts heavy constraints on the fuel. JP10 is a possibility.
I'm a bit surprised that you plan to design or run a liquid rocket engine but ask such questions... I too suggest to read and think more before going maybe on, and only if you get much more knowledge.