@chessguy
if u don't understand the language just don't leave it -- use google translate.. ha ha
just go the link..
https://splinterlands.io?ref=iampolite
and purchase your starter pack (A pack of 30 basic cards to get you a kickstart).
then check this out..
https://splinterlands.io/?p=gameplay

well I can't tell u what i learned in 9 months but yeah before starting a real battle go on battle page and practice a lot...
with having melle atack guys in front and keeping the archers and the magic attack at the back...
now going with a ranked battle..

every time u play.
if u win u'll earn some rating u loose u lost some rating..
on the basis of rating u will have you leagues and season rewards..

also as @marianaemilia said every time u played ur DEC capture rate drops.. basically it is a % of how much u'll get from your rewards if it is 100 then u'll get all your DEC reward if 50 then u'll get 50%.

but i say don't let them drop over 80%.
also complete daily quests.

now upgrade ur summoners (read the gameplay link to learn about summoners and mosnters.)
so upgrade them in order to use higher level monsters.
also join steemmonsters Discord.. here you'll find here a lot of guys who will help you when u got stuck

well that's it for now.
let me know if u need more assistance.