Looking for an intro to Hadoop

[#1]

I am looking to use Hadoop as a new way to store data for my company. Before I can delve into the details of this project, there are several questions I need to get answered. For example, we currently have a Microsoft database, is it possible to implement a data lake and create a hybrid type solution with Hadoop? Or would it be easier to just start over with Hadoop? Second, What tools are available for security? How do we make sure the data ingestion is secure and the data is high quality? Also what are some tools for data analysis and data mining using Hadoop?

Sorry if these qiestions are general, I am pretty new to this software. Any Answers are greatly appreciated and any links or literature to help me on this topic would be helpful as well.