any bike mechanics on here need some advice

Spark, as advised take the spark plug still connected to the HT lead and loooking at the electrode end you should see the spark jump across the electrode when you press the starter button with ignition switch on, which confirms functionality of the spark plug, that the plug gap is adequate and that there is naturally electricity flowing down the HT lead, this is with the lead on. You can check the HT lead against any ferous metal object to check that there is a spark, by exposing the metal cap within the HT lead that fits over the spark plug and placing the exposed contact a cm or so away from the ferrous metal obkect e.g. engine.
For fuel, check that there is fuel in the tank, that it's flowing down the fuel line and into the carby or injection unit if it's an EFI unit. If you are cranking the engine and inducing a flooded condition by using the throttle when the engine is cold, then you should experience a strong petrol odour wafting about. This in itself would be suggestive that there's fuel. As for timing, you got that right, there will be a marking in terms of TDC etc. Checking compression is better done with a gauge but a finger placed against the spark plug hole would work. Another thing is how were the valves and valve guides with the you had the head off? How's the air filter, clean, dry or soaked in petrol, If you have a wet air filter element and strong petrol odour, then go with WOT - that often works. If the petrol might be stale, or has water in it, get some petrol treatment like sea foam... and have you checked that kill switch. It might have been knocked into the close position.