Use of the ALM UI front end and use of the ALM Site Admin UI write to two different log file directories. The location of these directories is usually on the ALM application server, and you can find the location through the Site Admin UI, looking on the Servers tab.
Some changes made within a given project through the ALM UI can be found in the AUDIT tables for that project. AUDIT tables are specific to a project and audit activity that occurs only through the ALM UI front end. What is audited can be customized to some extent. If the project is not already configured to track changes through AUDIT, adding the configuration does not give you auditing of changes that happened in the past. You may be able to find some of those changes through the verbose log files, but that also depends on the logging level that has been set for those files.
There is no database table like AUDIT for activities that happen through the Site Admin UI (i.e. Create Project). The only tracking of such activities is through the log files created by Site Admin (see first paragraph or this response).
(Opinions and information contained in this post are wholly my own and do not reflect the opinions of my employer.)