Hello everyone hope the holidays did everyone well and updated some rosters. I can say that I’m sitting pretty well at this point as far as heroes but there can be a frustrating process of who to level and when. At 10 months in game now here are a few pointers that can help you out early an help you not feel “stuck”
1- a power rating of 500 across the board will give you a 2700 team + whatever troops you have. at this point will be able to farm the first three levels of Atlantis normal which has a better drop rate for backpacks than season 1. this level can be achieved with no ascension items needed other than customary beginning ones.
2- a power rating of 550 will give you a 2900 team + troops. this can be achieved by getting a set of 4 star heroes to 60 in their second tier.
At this rating heroes specials will definitely come more into play in raids and wars and you will begin to feel the power/lack there of said heroes thus giving you the experience to decide what heroes work best for you playstyle and who you will need to focus for events.
3- 600 power rating you will have a team at 3200 + troops. YOU CANNOT REACH 600 WITHOUT ASCENSION ITEMS. at this point focus on heroes you have had most success with and make sure to cover the 30 hero spectrum so that you have heroes for events/wars/titans. 4 stars will have to be in their final tier to reach this plateau and 5 stars will be in the middle of there third. note that at 600 you can fight maxed level 5 stats with certain heroes so you will definitely have tons of build options to learn as you war and fight at this level. focus on heroes with buffs/heals abilities to help your team in more ways than just offensive power.
After that it’s the final stretch for your heroes but if you stick to those ratings and take your time you not fret as much about ascension items as the will pace themselves out.
4-DO NOT BE IN A HURRY. if you do not have patience this is not the game for you. people wanting to be able to get to the TOP DOGS withing a month of arriving will be sadly disappointed, but after a good 6 months in you should be able to do fairly well in most aspects of the game and have an idea of where you wanna head with your heroes.
other pointers I could think of are
15-8 hard mode in Atlantis gives 30 to 35 troops per run.
get to training camp 19 as fast as possible 
season 2 stage 1 has the best backpack drop rate from my experience.
SET A BUDGET AND STICK TO IT. good rolls bad rolls will happen, as long as you set a budget and understand all events come back around. if you didnt get em now you will have a chance to get them later.
good luck out there.