An atom of sodium-23 (atomic number = 11) has a positive charge of +1. given this information, how many
electrons does it have? how many protons and neutrons does this atom have?

Proton number is the same as atomic number = 11
as electrons have a mass which is so small its counted as 0 and protons and neutrons relative mass is 1 
the number of neutrons = 23- 11 = 12 neutrons
In a neutral atom the number of electrons= number of protons but here we have a +1 ion so there is one less electron then proton therefore the number of electrons = 10