Do you still have a wifi icon on the lower right side of the task bar?
If you deleted the task bar, that is unrecoverable, in it's default form.
Initially did you right click on the task bar and then change the wifi icon using the resulting menu?
If you still have a task bar you can add a wifi icon, although it will be different than the original.
Right click on the task bar, then select Add/remove panel items, which will give you the panel preferences box, select panel applets, then click Add. this will give you a list of available plugins, scroll down to Manage Networks and click Add. Follow the same procedure for any other applets you wish to add to the task bar, Example- Temperature Monitor
And welcome to the forum