The Maruti Suzuki Dzire is an excellent, comfortable car that’s more spacious than the Tata Tiago, and has a larger boot too. Its engine is smoother, more refined, and more fuel-efficient, and being a Maruti car, your after-sales experience is also likely to be relatively fuss-free.
As your first car, go for the Dzire. Its overall user-friendliness and its more premium experience will make you feel like you’ve spent your money well.