Bitcoin removed the built in miner long ago. You can mine with an external CPU miner, a GPU miner, or an ASIC miner
on your private blockchain. For BTC you need an ASIC.

The target difficulty will change depending on the rate blocks are found, but it takes a long time at low hash rate.
1 is probably the default starting difficulty and it hasn't retargeted yet. The 10 minute block time isn't really the issue,
it's how long it will take to find the number of blocks required before retargeting occurs. You could change the parameters
to better suit your mining power.