Hi Inkey5 ....welcome to the Club
- Battery drain, quite possibly the laying up of the car for a length of time has caused the battery to sulphate and discharge.
Either use a battery conditioner (not a charger) on it and see if it recovers over time or replace with a new one
Also, once charged then you can look for a drain-source using a multimeter - also check earth straps and connection points on the chassis
Oil service and fluid checks are always advisable after laying up a vehicle - also a chance to check over the car and find things to address in the near future
Coolant level should be halfway within the expansion bottle and/or at the top of the radiator when you remove the cap
Good to have you onboard and keep us updated on your progress