After two months of being parked up it is likely that your 12V battery has gone flat which is why the key fob will not open the door. The manual key is the back up for this situation but as the physical door lock is not used often it is possible that the barrel has seized, so we would suggest spraying a penetrant such as WD-40 into the barrel and trying the physical key again. On some vehicles you may need to pull the door handle while turning the key to make it operate. If this is unsuccessful you can try the passenger door or boot lock as alternatives. If you still cannot unlock any of the doors you may need to call a breakdown service or automotive locksmith, and once you have access it is important to recharge the 12V battery so you can use the vehicle as normal.