Suggestion is not to go for a bike with a power of over 60HP for first time riders. Easier to learn with a bike with smaller power. Going with either a 150/200/250/300/390/500 is fine.

The smaller the capacity, the cheaper and usually goes the same way the other way around.

If you want the most out of the below RM30K learners bike, the bigger capacity should do better.

If you're a beginner in sportsbike arena, and are not that much into motorcycles, go with the more popular ones as they would be easiest to maintain (yes, I mean ninja/z 250/300).

Single cylinder bike usually will sound more like a motorized grass cutter compared to twin cylinder bikes. But the differences in terms of sound aren't as apparent when compared to 3 and 4 cylinder bikes.

Bigger bike usually uses bigger tires too so keep that in mind if you do travel a lot and have a rather constraint budget.