You now need to figure out what IP Address your Pi was assigned on your network so you can connect to it. For this you'll need to login to your WiFi router and access the DHCP lists.
Unfortunately all routers are different and we are unable to provide specific instructions. If you have difficultly with this, you can contact your internet provider and they will be able to provide instructions for your WiFi router.
If you have added an HDMI monitor & keyboard to your Pi, you can login using the username pi and password raspberry and then type the command "ifconfig" and hit enter. This will return your network interfaces and their IP Addresses.
Once you find your IP address, write it down you will need this to login to your Pi.