OP if you’re in India it’s probably easier to get a cheap Redmi that’ll be much more modern. My se2020 lags pretty often at 78% health.

The se 1 was around the 4s size iirc. The se 2 and 3 are iPhone 7 size, much “larger”.

As long as you aren’t downloading suspicious or weird apps, you’re likely fine. True for pretty much any Os.