The system automatically capitalizes the first letter of a word while indexing. That includes the first word in a name and any word after a space, such as an initial, a middle name, or the second word in a place-name.
If you delete the letters you've typed and begin again, the first letter does not automatically capitalize.
The only time capitalization is critical is in certain military projects, such as the US, Mississippi—Department of Archives and History, World War I Service Cards, 1917–1919 project. In this type of project, combinations of upper and lower case letters identify the military unit names for the military unit field in the batch. You need to enter the letters exactly as you see them, including capital letters.
With the exception of these military records, you do not need to correct capitalization when you review batches.