Hi, you can check this resource: If your iPhone, iPad, or iPod touch won’t connect to a Wi-Fi network
Are you able to connect to other Wi-Fi networks aside your own? How about mobile data, does it work?
You may need to contact your mobile carrier as to why you're only getting 2 bars for signal service.
Download the latest iOS update on your phone, go to Settings > General > Software Update.
If the issue persists, you may need to restore your phone as new:
How to back up your iPhone, iPad, and iPod touch
Restore your iPhone, iPad, or iPod to factory settings
You can also bring your iPhone to an Apple Store or Apple Authorized Service Provider to get it checked. Book an appointment at getsupport.apple.com or use the Apple Support app.