First check the oil, if it looks black & sludgy, change it and the filter first.
Next, pull the spark plugs out, check if engine can turn over by hand. If so, squirt a little engine oil into each cylinder.
If not, I would pull the head off for a look.
If standing for more than 6 months I would prime the oil pump before trying to start it:
Remove oil pipe banjo bolt from block,
squirt motor oil into the block until hole is full,
with 4th gear engaged, push car backwards for 2 revolutions of the fan,
squirt more oil in, refit bolt but leave 1 turn loose to let air out.
Select neutral.
Crank engine for no more than 20 secs with plugs out. If oil flows out around the bolt, good news- you have oil pressure, tighten it up.
If it just gives 1 burp (what oil you put in) and no oil flow, I am sorry but the oil pickup strainer is plugged with sludge. Engine strip time....
