I am having trouble to find my voice type, I don't know if I am a baritone or a tenor. I have 30 years of age. My lowest note that I can support is G2, but my comfortable note starts at A2-Bb2. I feel like I strain at F#4, my second passaggio,so literally i am in my head register at F#4, and I can mix up to A4-B4 in my good days.
You "would like to get some classical lessons for opera"? Well, do so. Your vocal coach will hopefully be much more qualified to answer your question than strangers on the Internet.
Comparing your voice to a lot of the Baritones and Tenors I've heard I'd have to say you're definitely closer to a Tenor.