dont worry bro im from 900 mmr continue play for almost 2years to reach 4k ...
there are every thread in every range of mmr.
1k to 2k just play any carry to farm till end and overcome the problem (basic mathod)
2k to 3k choose a jungle hero ward for the sight u only need even u are jungle.
3k to 4k need study the thread of pro using now, think ways to counter hero and let suport get some creep for ward and shoe. ( 3k stage suport is begginersupor since everyone play carry since 1k-3k)
sharpen ur skill (reflection, calm down, forecast skill, item situation, xpm&gpm control.)
to 1k until 3k player warding is not much important, because people action will be easily to forecast such as gank. most importantly is understanding about hero capability.