Normally the goddess/god chooses you, not the other way around! Gods are interesting entities and they usually start "calling" the people they take interest in. That way "the friendship" will work the best.
But in this case I would suggest you to maybe give little offerings to Athena. In Greek it was normal to sacrifice animals to the Gods and Goddesses but I don't recommend it. Give some meat offerings instead and share a meal or a drink with her. Give maybe olive oil and fruits to her. Also talk to her and pray to her. Athena will definitely make you know if she's interested in you.
Research her. I know her symbol is an owl, so perhaps setting up an altar to her and having an owl on it. Or giving offerings she enjoys [olives] but you should try reaching out to her before going 'I like Athena, I'm going to worship her'. Light some incense she likes and ask her if you may follow her. Meditate and wait for a sign. Repeat this process for about a month or until you receive a yes or no. Never just assume.
If you receive a yes you can begin to worship her in the best way you see fit. Make an altar to her, plant olive trees [If they grow in your area] make houses for local owls, daily prayer/offerings. As you grow closer with her you will learn other ways to worship/honor her, but those are some basic ideas.