Read CSV file from documents and create records

Please try the below example. Create a csv file on documents and use the below code to create records.

Document doc=[SELECT Body,ContentType,Description,DeveloperName,Name FROM Document WHERE Name = 'Csv File'];
String[] columns=doc.Body.toString().split('\n');
String[] columnNames=columns[0].split(',');
columns.remove(0);
List<Sobject> lstAccounts=new List<Sobject>();
for(String str:columns)
{
	Account acc=new Account();
	String[] fields=str.split(',');
	for(Integer i=0;i<fields.size();i++)
	{
		acc.put(columnNames[i].trim(),fields[i]);
	}
	lstAccounts.add(acc);
}
if(!lstAccounts.isEmpty())
{
	insert lstAccounts[0];
}