Here is a guide that most players will wish that they had when they started.
IMPORTANT: Do not spend any advanced summoning scrolls or shrine totems as you will need them to get top tier heroes later in the game during events. Legendary scroll events exist as well but early on you will likely need to use these scrolls to get a full S tier team. Cube events have not shown up yet, but they could likely come soon as the game is still in its early stages.
Step 1: If you are willing to put some money into the game, buy the monthly pass. This will give you a much needed early boost in getting gold which will become very scarce mid-late game. If you wish to buy Yuko in the beginner package she is good and you will use her for a while but you will end up swapping her out mid to late game. If you get the monthly pass you have access to 4x Midas Touch. With the privilege card this becomes very worth it to buy all three tiers of gold every eight hours.
Step 2: If you are free to play start here. Go to campaign and push it as far as you can with the basic heroes you have. Once you lose a fight, go to Abyss and push as far as you can. At this point you should have some resources to upgrade your S tier heroes with which you will start with one or two of. Look at the tier list and push the higher tier hero levels first and then the lower tier heroes. Go back to campaign and rinse and repeat. Once you have run out of resources and are stuck in both campaign and abyss go and make sure you have done your daily quests and have collected your free challenge pack for completing a campaign stage.
Step 3: Gear and runes are very important in this game, but not all gear is created equal. I would not recommend putting any resources into enhancing any gear that is not Orange tier (top tier). Save your gold and Equipment Crystals for those pieces because very soon you will be running short on both of those resources and will not want to have wasted any on red and below. Runes on the other hand never become obsolete. Focus on the life rune first, then attack and full attribute resistance. On select characters that have skills that are crit based you may want to buff a crit chance rune and crit damage rune for that character. End game speed is important but early on focus on those.
Step 4: Make sure to get your monthly quests done. I would suggest skipping the cube monthly challenge your first month and saving your cubes for the second month. Tavern quests though I would recommend picking up any 4* or higher quests, and refreshing anything 1-3* that does not have gems.
Step 5: Upgrade your Destiny Spring and Gem Lode in your Sanctum. These will come in handy later on in the game. I would not recommend putting any resources into Hero Relics though. IMPORTANT: In The Black Market always buy the advanced scrolls, Legend scrolls, basic cubes that cost gems, and arena tickets. If you can afford it, get the advanced cubes but only if you have massive stores of gems > 15,000.
Step 6: Destiny Circle: Focus on HP and Attack getting Life Force and Lethal Strike to 60 and then focusing on Life Prayer and Warlord Power to at least 20. At account level 80 check out your class circles and you will likely want to buff your priest class first as they are always needed on your team. Try to unlock all aspects of the priest class and max out their skill buff. Afterwards think about what your end game team you would like to have and focus on buffing those class circles. At some point these will cost you a lot of gold and Mysterious Orbs (used in upgrading destiny circle) and you will want to buff your attribute resistance and attribute attack. Which one you focus on will depend on the team you have.
Hopefully this was informative and best of luck to you and your team! I am BloodPrince in the game and you can find me on IOS servers 1, 5, and 6.