You should do the compression test to see what sort of reading you gert, If it is very low. Like well below 100 psi then do the wet test by adding a few squirts of oil in the cylinders. This helps determine if a low reading is the valves or the rings. If the compression comes up a large amount after you add oil then the low compression is a result of bad rings. If it doesn't come up much then it's the valves.
If the bike has set very long it may have low compression, like 100- 125 psi, both side close to the same, and just running it for a few hundred miles may bring the compression up to the 140-150 psi range.
If the bike runs, put in the oil and warm it up. Do the compression test as the engine is.
Then do it again with a few squirts of oil in each cylinder.
Report back what your readings are.
Leo