Can I replace a 26"/2,0 rim with a 26"/1.75 rim? My bike's front rim bent and I want to replace it.

I bought a Apollo Summit 10 for 250$

After some time the front rim bent when I fell down on the street and when I asked in the market its 120$ for a 26"/2.0 aluminium front wheel.

I searched for the rim online and i found one that is 26"/1.75 Can I use 26"/1.75 aluminium rim for the same Tyre and Tube?

Is it going to work properly ?
2.0 is the diameter of the tyre/tube in inches.  So a 1.75" tyre will be smaller and slimmer, and probably a little faster.

26" is the diameter of the whole rim, but check the tyre for its ISO number to be sure.  Its likely to be a ISO-559 size.

answer: yes that rim will probably fit fine.  You'll need to check and adjust rim brakes, or if its disc brakes then that needs to be right too.

Front wheels tend to survive better than back wheels.  If you're after a replacement wheel search out a local bike cooperative.  Our has dozens of spare front wheels and a lack of good rears.