You as the creator and holder of copyright of your work can[2]:
Make copies (for example; download, PDF email attachment, photocopy or scan)
Distribute copies (including over the internet)
Prepare derivatives based on the original work
Perform the work publicly
Display the work publicly
You cannot perform any of the above acts on other people's work without infringing on the owner's rights. The ways in which you can use copyrighted works are if it falls under Public Domain, Fair Use, or if you receive permission from the author.
Public Domain
When a work enters the public domain, it no longer has copyright. These works can now be copied, distributed, performed and displayed without permission. This can happen when a work expires, which is the life of the author plus 70 years for works created from 1978 onwards.
More information on when works enter the public domain along with tools to help you understand if a work is in the public domain.
A handy chart of copyright term.
Fair Use
There is a Fair Use doctrine under U.S. Copyright Law that states that sometimes use of copyrighted works falls under "fair uses". This could include criticism, teaching, and research.
More information on Fair Use with a Fair Use checklist.
A tool to help you decide if you are applying Fair Use.
The College Art Association created a resource portal and guidebook for navigating best practices for visual arts professionals, including artists, on how to apply Fair Use. Be sure to look at the Making Art section of the guidebook.
Permission from the author
Authors can transfer all or partial copyright of their work to another party. To do this, you must contact the copyright owner and request permission of use.
A guide on how to obtain permission of use from the U.S. Copyright Office.
More information on how to obtain permission from the author with tips on various medias.
Things get tricky here. Artistic works can blur the lines of copyright law or knowingly infringe on copyright. If you choose not to ask for permission from the author, be sure to know what you are doing and why before engaging in either appropriation or parody.
This resource has links to various legal cases pertaining to appropriation art and parody.
This resource similarly explains instances of Fair Use for the right to parody.
Reference:
[2] Schmidt, L. & Symulevich, A. (Last updated: 2020, September 21). Copyright Basics. University of South Florida Libraries. https://guides.lib.usf.edu/copyright#s-lg-box-70889