Suzuki Celerio jerky at low speeds

Hi,

I picked up a 2018 Suzuki Celerio a couple weeks ago with only 8,000 miles on the clock.
It was driving fine for around a week but it's started becoming quite jerky during low speed driving in 1st and 2nd gears, the car is only 2.5 years old with 8,000 miles on it so I thought surely to god there can't be owt wrong with it.
Is that just how these cars are? I notice there's a lot of throttle lag also, press throttle halfway gives me like 25% power halfway to 100% gives me the other 75% power but my local mechanic says "that's what all modern cars are like"....hmmm ok I can handle that but surely it should be jerky at low speeds? It's becoming very frustrating very quickly!

Also is it normal for the car to make warbling noises on overrun at lower speeds? My 19yr old Micra never done this and it also pulled away far easier than my Celerio does... I could pull away almost from a stop in 2nd in my 1litre 4 cylinder Micra whereas in this Celerio anything under 20mph seems to call for a downshit to first which is 1) annoying and 2) makes for jerky driving, but at low speeds it stumbles and almost stalls when I try to speed up from 10mph in 2nd gear.

Is all of this just normal and the Celerio is just a crap car or is there something wrong with mine? This is my first Suzuki and I'm really not impressed so far, but no idea if this is characteristic or a fault.