Please help

I only recently got the bike and i am useless with mechanics.

I started the bike this morning on choke all seemed well and when turning the choke off the bike cut out, it was about 46degrees which would usually work.

I thought maybe it was just not warm enough so started it with some revs to try and get it idling but it kept cuttign out.

Adjusted the idle seemed fine but when riding it still kept cutting out.

The other problem is when pulling the throttle back getting the revs up it will stay around 5 thousand which was a nighmare riding especially for a beginer because they would not drop when at stand still.

I played with the idle and can get the revs to either under 1000 so it cuts out or over 3000.

Please help because i am very confused and not sure what to do.