Second hand car purchase tips

As the title describes, thinking of buying a second hand car muna for my first car - is this advisable or should I go for brand new?

Any tips? Wala din akong kilala na mekaniko so not sure if there are any reliable services that I can use. Also looking at AutoDeal and other platforms using filter na almost new, basta if ever bumili ako ng second hand car less than 5 y/o lang, low mileage. Is it okay to buy repossessed cars?