Hello and welcome to JA!!!
I'm Billy and i will help you with this.
Cold start defects can be caused by multiple reasons, basically everything that weakens the engine a bit will show on cold start, as at this stage the engine will be barely operational.
The main things to check on a cold start problem (stuttering until engine is warm), are the following:
- spark plugs.
- coil packs.
- clean throttle body
For the first thing, you have to remove and check/replace if necessary the spark plugs, as they could trigger same symptoms you are having.
Now to check coil packs, you can spray them with a bit of water, while engine is running and look for changes in idle, or even visible spark coming out of the coil
To clean throttle body, you will have to remove air filter box and hoses coming to throttle, and then clean thoroughly using WD40 and a toothbrush.
Having done the following, your problem will mostly be resolved (i think from step 1: spark plugs)