I am Argentine but I barely know Spanish despite understanding it. Any tips for my baby and I to learn Spanish together?

My parents are from Argentina and they wanted to Americanize me as much as possible, so I grew up only understanding Spanish but never speaking it. I want my baby to be bilingual, since he is half Argentine and half Irish. However, like I said, I only understand Spanish and don’t speak it, so it would be hard to do the “one parent one language” approach. Any tips on how my baby and I can learn Spanish together?

Edit: he is 9 weeks old at the time of posting this.