How high up do we have to go before entering the earth’s atmosphere ?

Zero inches. You are IN IT right now.

Just one toke and you are high enough to feel the atmosphere.

The atmosphere starts at the surface (whether that's land or sea), and gets thinner as you get higher.   Space officially starts at 100 km altitude, but there's still some atmosphere quite a bit higher than that, even...

Even at 430 m below sea level, which you would be on the banks of the Dead Sea, you will be in the atmosphere. It is the atmosphere you inhale when you breath in. It supplies the oxygen you need.

Your in the Earth's Atmosphere standing on the Beach at Sea Level.

The Earth's Atmosphere goes from the Surface of the Earth to about 62 Miles.

100 kilometers or 62.i7 miles. It is called the Karman line.

The atmosphere?does not have an edge and the height varies. There's enough air in. low earth orbit to create enough drag that can slow down satellites, the ISS and orbital debris enough that they fall out of orbit. 

https://en.m.wikipedia.org/wiki/K%C3%A1rm%C3%A1n_l...

Someone else's answer is off by a factor of 100. Outer pace is not an absolute vacuum. 

If you mean exiting the Earth's atmosphere, that depends on which of the 6 layers you are referring to.  I'll assume you mean the point of entering outer space which is 6,200 miles (10,000 km) above the surface where the final particles of our atmosphere are left and the absolute vacuum of space begins.

You’re breathing the atmosphere right now

FYI:  It's all atmosphere...