Hello everyoneI'm a student and I am trying to learn AutoCAD from web tutorials as much as I can at home and after I finish High School to follow some drafting courses.So I need to join the 2 arched blocks together. Is there a command to help me do that?Sorry if I didn't explain that clear, hope you understand.Thank you!

One option would be to extrude the cove-like profile along the path of the partial circle. 

Or revolve the profile through 90 degrees

I did it using the Revolve command because it appeared easier and I'm only a beginner but I believe that someone more experienced could do it with extrude or other commands too. Took me some minutes until I chose the right base points . Also do you think that it's possible to earn money from freelancing websites when you gather some knowledge? How should I know when I'm ready to do that and what do you recommend me to focus on reading/learning about?Thank you.

What kind of freelancing?  BTW...this can be very cutthroat.  You had better be good, fast and affordable.You'll know when you're ready to do it only after you have put in the time to learn not only the basics but advanced techniques as well.