1994 Toyota Corolla Hard-start engine problem

Following are precise model details of my car:
Model E-AE100-AEMEK
Engine# 5A-SE
Frame # AE100-3225721

My car has a hard-start problem. if the engine remain off for some time. I have to press the accelerator for about 10minutes before it can start properly.

Idling is also very unstable, sometimes it runs normally while at other times it drops too low, causing too much engine vibration.

What is the problem and how can it be fixed?

Thank you.

Justin