takaeri

Hello everyone, Im new to all of this and just got my own telescope, its 130/920 eq2. Im able to clearly see the moon and jupiter (barely) but only when I use 25mm with an extension tube, same goes for terrestrial objects such as distant chimneys or mountain tops. Besides 25mm and an extension tube I also have 10mm, 1.5x erecting lens and 2x barlow lens but no matter what i use and combinate, the image is out of focus and blurry (im seeing black circle with like 4 strings I read somewhere that Im seeing secondary mirror). Any ideas what should I do?