To run the Oracle Database in MacOS, you have different choices. The most easy ones are:
Oracle Cloud Free Tier
You can setup your free online Oracle Cloud Free Tier environment and configure your local SQL Developer installation to the Cloud environment. https://www.oracle.com/cloud/free/
For further information about the Cloud Free Tier environment, check the posts https://dgielis.blogspot.com/2019/09/best-and-cheapest-oracle-apex-hosting.html from Dimitri Gielis for detailed instructions on how to do that.
Vagrant/VM (Intel only)
For a local setup, this is the most easy way in my opinion, since I'm not an experienced user of Docker. Oracle has made Virtual Machines available for free, https://github.com/oracle/vagrant-projects
Use the OracleDatabase v21.3.0-XE or v21.3.0 image, if you need the database only. If you intend to use APEX as well , which I can highly recommend, install Oracle APEX after running one of those database vagrants or use the OracleAPEX (v18.4.0-XE) image, if you need it out-of-the-box.
Docker
If you are known to Docker or want to learn it, you can follow the link in @Bjarte Brandt comment https://github.com/bjarteb/oracle-apex-ords. The setup documentation in that link is quite comprehensive.
Update due to Apple's M1/M2 processor
Since Apple introduced new M1/M2 mac's based on the ARM cpu architecture, for a couple of years the only option available was the Oracle Cloud Free Tier. Unfortunately, VirtualBox VM doesn’t support the ARM architecture yet and it doesn’t work with Rosetta..
(18/04/2023)
But...
I hear rumours these days that indicate that it is now possible to run an Oracle Docker image on an Apple Mac M1/M2 using Colima.
I don't own an Apple M1/M2 MacBook, so I cannot verify if it works and/or performs well. Performance still seems to be an issue, but it seems at least now possible to run an Oracle Database on an Apple M1/M2 device. For more information, follow these links and read on:
https://github.com/gvenzl/oci-oracle-free#oracle-database-free-on-apple-m-chips
https://www.salvis.com/blog/2023/04/16/oracle-database-23c-on-a-mac-with-an-m-series-chip/
https://www.dbasolved.com/2022/09/running-x86_64-docker-images-on-mac-m1-max-oracle-database-19c/
https://levelup.gitconnected.com/docker-on-apple-silicon-mac-how-to-run-x86-containers-with-rosetta-2-4a679913a0d5
(13/09/2022) Oracle SQL Developer 22.2.1 is now natively available for MacBook M1/M2 clients. Previous versions would need Rosetta to run. Unfortunately, no signs for VirtualBox supporting ARM yet..
If you own a MAC based on the 'old' Intel processor, you would still have all the options available.