Sweeps make it much easier to clear dailies and time rifts.
The trick is to just accept that you dont always have to advance the challenges in the game.
So many low tier upgrades require an excess of resources, that just chilling for a while can be useful.
For instance, I sat at lvl 50 Aniki Gyms until I hit 70, because all the silver and gold resources are important for advancing your soldier training.
Similarly, I sat at lvl 50 bonding realms as well, because I needed a lot of copper and silver keys to level up my first 2 bonds on my main team and to upgrade a handful of useful bench heroes as well.
The biggest thing you will feel pressure to advance in will be time rifts, because class advancement is critical to unlocking skills for individual heroes, but even there, if you join a friendly casual guild, you can simply use your guild points in the guild store to buy the class resources you need.
My suggestions are:
Allow yourself to slow down when the challenge gets too high, this game doesnt give away free wins like most gacha.
Sweep your dailies to max your resources and account exp.
Save your burgers for advancing, dont use it to sweep if you can help it, save them for when you want to advance your time-rifts or the main story (or unlock the next level in secret realm).
Join a guild (guild events cost zero stamina) and sweep the towers for guild points to buy a variety of different resources.
Beyond this, my only other advice/warning is that there are "hell levels", from lvl 52-lvl 62. If its frustrating, just give up on advancing, sweep your dailies and save your burgers; eventually your daily quests give enough account exp that youll come out the other side and you can begin to focus on advancing again by the time you hit lvl 65-70.
This game is def not for everyone, but for me, this is the only mobile game thats ever mananged to keep my interest for longer than a week or two. >I also appreciate there is a pc client.