questions about visas when moving!

hey everyone, new to the forum but ive been reading here for a while. great site you guys have going on here.

im getting married to a spanish citizen in spain & moving there permanently and i have a question i was hoping someone could help with.

do i need to go to a Spanish Counsel here in the states and apply for a visa before going, or can i go to spain on a one way ticket with a tourist visa and get married there and renew/change my visa status once im there?

will they admitt me into the country with only a one way ticket?

can anyone help?

thanks!