Connect Pi to WiFi

#iwconfig

# sudo iwlist wlan0 scan
update /etc/wpa_supplicant/wpa_supplicant.conf  for open wifi

network={
    ssid="testing"
    key_mgmt=NONE
}

or the output of this command if use psk
# wpa_passphrase "<SSID>" "<SSIDpassword>"
see
https://www.raspberrypi.org/documentation/configuration/wireless/wireless-cli.md


Check if you can connect
# sudo wpa_supplicant -iwlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf

#sudo /etc/init.d/networking restart


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Time sync

1. Open rc.local file
   sudo nano /etc/rc.local
2. add following line to the rc.local file
   sudo date -s "$(wget -qSO- --max-redirect=0 google.com 2>&1 | grep Date: | cut -d' ' -f5-8)Z"
3. reboot the Rpi
   sudo reboot

source: https://raspberrypi.stackexchange.com/questions/47542/raspberry-pi-wont-update-time

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go to or create /etc/apt/apt.conf.d/10proxy then add

Acquire::http::Proxy "http://username:password@host:port";