Make sure you're viewing and searching the latest version of the manual
here.
Sometimes old versions of the manual show up in web searches, and there is at least one web domain that tries to mirror the manual but looks suspicious. Unfortunately, when you submit searches through the official manual, you sometimes get warnings that the information you're submitting isn't secure. I think OOTP Developments might need to update its security certificates, which is why that message is probably appearing. However, since you're only submitting keywords, you can allow the searches to go through.
You can find answers to most of your questions about the financials and free agency here:
https://manuals.ootpdevelopments.com...age=financials
https://manuals.ootpdevelopments.com...ge=free_agency
However, some MLB rules and contract or financial concepts are complicated, and they might not be explained in full detail in the manual. If a definition isn't clear in the manual or you can't find the right explanation, try a web search and look for results that contain a detailed article or section on the topic.