Is gender the only difference between "Jestem turystą" and "Jestem turystką"?
why isnt it 'jestem turystem'?
The Nominative form is "turysta" - and despite ending with -a, it's masculine. Feminine is "turystka", so "Jestem turystką".
turysta is a complement. s turysta (with squiggle) instrumental or what?
"turysta" is the basic, Nominative form ("Turysta jest wysoki" = The tourist is tall), "turystą" is indeed Instrumental.