So there are no other decent pedals apart from the plastic ones that come with the bike ?
Plastic pedals are not great at all really, flexy material so power to pedal ratio is not the best, the grip pegs don't tend to be too robust, they're not brilliant at keeping hold of your feet in the wet & a spinning pedal on the shin or calf hurts. Plastic pedals also tend to be the very budget end of the market so would usually have cheaper inner workings too.
Your only real option for better flat pedals is metal ones that have grip pattern most suited to the shoes you cycle in.
Personally I really like the feel on my feet of old 70s & 80s touring type pedals. My only bike without them is my folder with folding pedals.
These were built well and cost a couple of quid at cycle jumbles.
Clipless (the cleated type) are the common upgrade but not all of us feel the need or benefit of them, I've done the Clipless thing and gone back to flats because it's easier to just get on and ride in whatever I'm wearing.
If you're into the lycra look & / or racking up big miles and not stop starting in traffic every few yards them don't discount them just yet, a consistent planted foot position, guaranteed no slippage in bad weather, pull up as well as push down pedalling, makes you wear shoes that are designed for cycling and not squishy or flexy while riding...
You can get going on Clipless for about £40 for a cheap set of pedals (shimano m520 are a good starter option) and Aldi or
Decathlon level SPD compatible shoes and see how you go, not lost much if you don't get on and it may be a revelation to you.