Best way to airport

If I am checking bags or need to go to the counter, I like to be there 2 hours early. With carryon only, I am good with 90 minutes early. But I am very conservative. From the counter or door to your gate will take no more than 15 minutes and a few days ago I did it in 10.

The trip to the airport from the opera (where I live) is 35 minutes and about 11.000ft by taxi. But I round it up to 45 when planning. In Budapest Uber and Bolt are nothing but taxis dispatch services with meters and licensed taxi drivers and yellow cars with lights on the roof. So, sure, use them if you have the app. I like CityTaxi as in 20 years, they have never failed me, and I use their app, but all are the same cost and same process. https://citytaxi.hu/

You could also use the 100E bus. That's the express bus to the airport that departs from Deák Ferenc tér which isn't far from the Opera. Give yourself about 10 minutes to walk or take the M1, maybe 10 min for the next bus and 45 minutes for the trip. All those numbers are rounded up a bit. Cost is 2200ft. https://bkk.hu/en/travel-information/airport-express/

Taxis take credit cards. The 100E Bus is not covered by your city pass but you can pay at the bus (there are assistants at the stop). The bus is free if you are over 65.

If you are departing out of 2A and the security area is a mess or its very early in the morning and its not open yet ... look to the left, and you will see a sign to security in Terminal 2B, and it opens earlier and generally moves faster. Both security lines dump into the same departure hall so does not matter which you use.

Terminal 1? Its a different airport a 15 minute drive away and its closed. But a beautiful old building.