Advanced 5th Edition

The Level Up : Adventurer’s Guide is an expansion on existing d&d 5th edition rules. This rule set is referred to advanced 5th edition, or A5E. For comparisons, the original 5th edition is referred as O5E.
A5E is completely compatible with O5E, for the most part players can ignore A5E rules and stick to what they know if they want. There are a few points of A5E rules that are worth pointing out.
The page number is listed as the page that is printed on the book. The PDF has a cover so add two pages when looking through the PDF.
Supplies
Page 229
Supplies are everything that an adventurer would consume on their journey in one day. Typically this is food and water, but could cover anything else that is consumed.
An adventurer can carry a number of supplies equal to their strength score.
Combat Maneuvers
Page 456
A combat maneuver is essential a combat spell. Everyone has access to basic maneuvers, which are the equivalent of cantrips, and A5E classes have access to advance maneuvers. O5E characters do not get access to maneuvers beyond the basic ones. 
Heritage and Culture
Page 26
By typical O5E rules, who you are and how you were raised is one and the same. For example, an elf was raised among the elves and is trained in things elevens know like bows. A5E splits this up into heritage and culture, so you can mix and match however you want. You can use either O5E or A5E rules for this when creating your character.
Destiny
Page 95
Destiny is a guide for role playing your character. While the overall campaign goal may be to defeat some evil dragon or save the kingdom, your character has their own goal that they are working towards. They may be looking for revenge, spreading the word of their deity, or just grow as a person. Doing something that aligns with you destiny awards inspiration, and fulfilling your destiny can award you with additional features.
If there is a destiny you want but isn’t listed, speak to the DM
Strongholds and Followers
Page 359
Once players have gained sufficient wealth, money can be spent on building a stronghold or hiring NPCs that can assist on the journey.
Spells
The A5E book has a spell list that is accessible to both A5E and O5E characters. Class restrictions still apply. Some spells in the A5E book are the same as O5E, some are new, and some are essentially the same but with minor changes.
There is more information available, especially in the combat chapter, but being aware of these points is all that you will need to know.