The “6 inch dobsonian” is a good beginner’s telescope if you want to save money and/or floorspace. It’s relatively light and easy to use. Be aware that you may outgrow it and yearn for larger and brighter images.
What you can see
The Moon looks fine with enough details to impress friends.
Venus and Mars are tiny disks.
Jupiter is a small disk. You may be able to see some weather bands (just) and the four biggest moons.
Saturn is small. You can just see the rings and some of the moons.
Deep sky objects (nebulae etc) are visible but faint.
Comets can look nice but they vary a lot.
Objective mirror: 153 mm (6”);
Focal length: 1200 mm;
Tube length: mm;
Focal ration: f/8;
Max practical mag: 250x;
Focuser: 2" Focuser with a 1.25" Adapter;
Finder scope: 6x30 mm;
Weight: 9kg (tube).
Dobsonain Base (assembly required)
25mm 1.25" Plossl Eyepiece (48x)
10mm 1.25" Plossl Eyepiece (120x)
2″ to 1.25″ Eyepiece adapter with M42 thread
2″ Tube Extension