Security and Privacy are two separate issues which sometimes overlap. In fact hundreds of apps have hidden trackers which can analyse behaviour and then give you specific targetted adverts. There are now also more sinister applications which can locate you through for example noise (ultrasonic).
Click on an app and then click on the report. It will tell you if there are any trackers!
However, most people think of security in terms of anti-virus software and although it is less frequent on tablets and phones it is growing. There are apps in the playstore which contain viruses.
Tom’s guide a trusted and reputable independent reviewer has these suggestions.
Before you install it, check to see if you have any other antivirus products on your device. You may be advised to uninstall these (if they are free), so as not to have any conflict with other apps and not to have too many processes running in the background.