For beginner choose between Wego and Active. For second hand prefer Activa. A 3-4 yr old Activa will cost around 25k+
If you are not bulky, you may also consider new Yamaha Ray or TVS Scooty Pep+.
PS: We have a Wego. 1 yr old. I Personally I feel its way better than Activa in handling.
TVS Wego and Jupiter are good but I prefer Wego. Jupiter has some nice color choices. The mileage is good but cant guess them after 2-3 yr life.
Have Activa which is good but mileage is around 45kmpl for one which is yet to celebrate 1yr. The Handling and road grip is great too. Older ones dont cross 35-40kmpl though.
TVS Scooty Pep+ is good too, though less power and weight. TVS Scooty Pep+ is easy to drive and learn. Have seen proper serviced Pep+ giving 45+kmpl after 4-5 years. Should be fine if you driving at 4o-45kmph.
Yamaha Ray is good looking like Honda Dio, Fashionable too. Same class as performance though mileage is like Activa or worse.
As of now TVS Wego is prefered for me. But as a beginner if you can get used to Activa then you will be fine.
As a beginner would recommend Pep +>Activa>New Wego.
One thing to note is that wego has metallic body which makes repairs easy. Most of the gearless scooters have plastic/abs body which cannot be repaired... only replaced.
^^ can't say about mileage as i don't keep track of it but service has been good so far. i missed service last month and there's a free one coming up... i'll see how these guys handle it this time around.