The main German word for “to visit”, the act of going to see a person or place, is “besuchen”. A “visitor” is “Besucher” (m.) and “company” (in the sense of “we’re having company”) is “Besuch” (m.). Specifically for visiting landmarks in order to see them, the verb is “besichtigen”:

– “Ich möchte dich am Wochenende besuchen.” – “I would like to visit you on/at the weekend.”
– “Ich besuche meine Oma.” – “I’m visiting my grandma.”
– “Wir hatten letzte Woche viele Besucher.” – “We had a lot of visitors last weekend.”
– “Ich kann nicht. Ich habe Besuch.” – “I can’t. I’m having company.”
– “In Berlin kann man viele Sehenswürdigkeiten besichtigen.” – “I Berlin one can visit many sights/places of interest.”

Note that “besuchen” can also be used in the sense of “to attend”, as in a school or a course.