Mazda 323 Astina 1994

Mazda 323 Astina 1994. My car has progressively gotten worse over the past 2 weeks on start up. Until now it doesn’t seem to want to start properly at all. When the key is in ignition the revs are irrational between 500-3000, jumping up and down. The sound it makes is a jittery choking noise as it revs up and down. It feels as though it constantly wants to stall.
As for the White smoke… This has become a common feature on start up of the car but only on the first use of the day… Whether that would be in the morning afternoon or evening. It doesn’t smell sweet and lasts for a minute or so. I havent notice any difference in the coolant level. I did fill up the engine oil recently as the light was showing on the dash… The level of the engine oil is between the F and L lines. Non of the fluids/liquids seem to be odd eg mixed oil and water, milky etc. any ideas as to what this might be would be much appreciated!