Hi there, welcome to our comunity!
Name's Vaatigam, though everyone calls me Vaati.
So you've started over a week ago and snatched 40 wins? Really nice. If you're starting this game, then my advice to you is to find a 5* named Edwin. He's fairly common and is versatile on many events, but he can be a bit costly over other 5* due to that, though if you get him it will be worth it for a long time.
If you want to rank, then my advice is to save on the blue flasks and clocks that you'll find ( named TE and Potions respectively) while gathering the more colorfull versions from either selling max 4* and goddesses that you may find (the three are Anu, Danu and Tartu). The later are used as currency on this game for namely everything, including cheap 6* that you may get while looking around.
There are guides in these forums, so look around and learn bit by bit. Don't charge in, as this game can be tricky if you don't look out.
It took me a month to get my first 6*, which i believe that it'll be the time you'll take as well. That is, unless you end up within the 600th ranks and win the easy 6*.