How I know if my phone is tracked?

How can I determine if my phone is being tracked? I've been feeling like someone might be snooping on my personal data. What are the telltale signs that indicate my phone is being monitored? Are there specific apps or settings I should check? Should I be concerned if my battery life suddenly decreases? Could this be a sign of tracking software draining my battery? I'm also curious about whether my internet connection could be a giveaway. Would slow internet speeds or frequent disconnects suggest that my phone is being tracked? I'd appreciate any advice or insights you could offer to help me safeguard my privacy.