My first mtb bike

So i just bought my first mtb bicycle yesterday, i want to hear some opinions from other people if i got a good deal

240 euros, 29" wheels, schwalbe tires, 2×9 shimano Alvio derailleur, shimano disc brakes (not sure what is the disc diameter), sr suntour xcm 30 front fork with lockout and preload adjusment

I have some things that do need work and if can get any tips on how to fix them
Front wheel isnt trued it goest slightly to the right then left and when shifting gears the gear indicator isnt showing what gear i am actually in its off by a few gears

Any help, second opinions and such are welcome, thank you 😀