Hey. That is a decent starting ground you got yourself there.
I want to give you a bit different perspective than most people, solely from my experience.
Back when I started in late September, I also pulled a lot in the beginning and very quickly got some 4 stars of each colour. I read all the forum advices about the necessity to build a solid team of maxed 3 stars first before working on 4 and 5 stars. I was stubborn to ignore them. And I did very well and not once regretted it. I landed in gold tier rides in almost no time, in November I was already able to finish advanced Morlovia. Now it’s almost 6 months later and I only have one 3 star maxed (Melia, and she came by when I already had couple 4 stars maxed). It doesn’t matter to me at all.
The 5 star I was working on was Magni and I think the key to my success was the fact that it was a fast sniper. 5 star healers or 5 star supports or 5 star aoe may not do well in those early stages, but 5 star sniper did great. After some time he was chewing through all those scary 3* freaks. Joon is 5 star sniper too. I also had Tiburtus very early in the game (he was actually the first 4 star hero I maxed) and also prioritized him over any other purple. Tib, Magni and Kelile were the key to my success, and none of them was 3 star.
Note that what I think also made my “rush” working was the fact I didn’t mind to buy occasional offers with guaranteed ascension materials. To level up 4 star and 5 star to their full potential, at some point you will be required to use items which are impossible to drop just by playing the map. They are quite rare and may hold up hero development for quite a while. If you don’t mind 10-50 $ offers once every few weeks, that may remove this issue for you as most of them comes with these ascension mats. And in no time you should be able to get to level where you can get these ascensions materials for free by finishing quests, missions etc (chance is quite low, but with little patience it happens) to further build up your development resources.
Key is also having an all team healer. Something I had no luck pulling for very long time. You are lucky to have very good 3 star all hero healer Belith, and definitely start working on her over any other green.
Again, the advice to ignore most of the new player guides is controversial and probably most people would tell you not to listen to me. I only post it because I did exactly that and it worked very well for me.
EDIT: this post is a snapshot of what I had after a month into the game: Need advice on which Red to focus (new player) My very first post on this forum 