In my opinion, having a high cholesterol level would predispose you to high blood pressure, which would be the issue.

Since you just started running 1 month ago, the reason you could barely last 2km is due to a poor aerobic base. Just keep running & you'll improve.
As always, a combination of aerobic & resistance training would be beneficial.

Do you strava? If yes, the activities in this watch does not sync to Strava.

Why not consider the Amazfit range of GPS watches like Amazfit GTR or Stratos 3?

Download Running Calculator from Playstore and put in your best time eg for 10km and it will populate your paces.

If you're starting out - which I'm assuming you are since NRC has you doing a 5k as a long run, then I would suggest following their programme.  Yes they're asking you to go at that 10 minute pace per KM although that's pretty much a walking pace.

I think these calculators are great as they provide objective paces for training.  But not at the beginner stage when you're still trying to get the aerobic fitness to run without taking breaks.

Also those paces are worthless unless they are used with properly designed workouts for what you're trying to achieve.

Sorry for the stupid question. Are there actually any smartwatches with built-in GPS below RM200? This is my first time buying smartwatches & I want to use it solely for Strava. If I have to stretch my budget it'd be up to RM300. TQ.