You buy equipment like that to learn, and you learn by doing experiments. You have done some experiments, and you have some questions. Now you have to find the answers to those questions by doing more and different experiments until you can explain what you are seeing.
Also bear in mind that the products you bought will have a range of operation, performance limits, and limitations on accuracy and precision. Your experiments should also be designed to discover those limits. No piece of equipment is perfect.
And really, the only way to learn successfully is to teach yourself. The answers you find by yourself are ten times more valuable than the answers other people may give you.