The abbreviations for creating a history timeline can be confusing. Here is the correct order, which will facilitate the organization of your timeline.
BCE-- This stands for 'Before Common Era' and used to be known as 'BC,' an abbreviation used to designate the years before the birth of Christ. The abbreviation BCE is just a secularization of the more commonly known BC. An important piece of knowledge to understand about this part of the timeline is that these years work sort of like negative numbers do on a number line; years labeled BCE get smaller as they approach more modern history. The bigger the number, the older the date is. For example, 500 BCE is older than 400 BCE, and an event that occurred around 8 BCE would have happened only 8 years before the birth of Christ.
CE-- This stands for 'Common Era and used to be designated as AD, or 'Anno Domino,' the years following Christ's birth. The numbers are like the positive numbers on a number line and increase as the years progress.
One last piece of information that will be helpful is to understand how the designation of 'century' works. When a historian refers to something that happened in the 19th century, they are actually referring to the span of years that take place from 1801-1900. For example, something designated as late 8th century would have taken place around 780 CE, but an event that occurred early 9th century would be around 800-820 CE.