Sorry to hear that your having troubles connecting to your wifi network. A few steps I would recommend would be to go to settings - wifi and if it shows your network tap on the little i inside a circle and choose to Forget Network, then toggle wifi off & back on again. See if that resolves it. If not you may want to reset your network settings by going into Settings - General - Reset. From there you can choose to reset network settings. Any saved wifi PWs for networks that your phone will automatically join will be erased so you will have to re enter the PWs.
Here are a few articles from the Apple support site as well.