Is there a minimum amount of XTZ required to begin staking?
A lot of new Tezos users ask this question because there certainly is a minimum amount of XTZ required to bake Tezos.
No, there is no minimum amount of XTZ required to bake Tezos.
To be precise, there is a minimum but it's very tiny.
You must pay a transaction fee when you delegate your account to a baker. This transaction fee is the cost to include your delegation order into a block and it's usually just a few cents of a XTZ.
This is the only cost involved in delegating your Tezos.
Now for the details.
Tezos has the concept of a roll, which is the basic unit considered for the baking lottery.
Each roll is made up of a certain number of Tezos tokens.
The amount of XTZ in each roll is decided through a Tezos amendment proposal.
In the initial Tezos protocol, a roll contained 10 thousand XTZ tokens. In 2019, an amendment reduced the roll size to 8000 XTZ.
Every roll is given an ID, something like a roll serial number.
During the Tezos baking process, serial numbers are randomly selected from the pool of delegated rolls. The baker who has the drawn roll ID delegated to them gets the right to bake the block.
Therefore, if you do not have a complete roll, you can't ever be selected to bake. In practice, this system establishes one roll as the minimum required amount to be able to bake Tezos.
There is no such mimimum for delegation. Anyone can delegate any arbitrary amount of XTZ to a baking service. The roll calculation is then performed on the baker's side.
Some newbies confuse the baking requirement with a delegation requirement. The latter does not exist.