New to me 7060 Power shift question

im new with the big horsepower machines, bought a a 7060 power shift with front loader , spikes and bucket, ac works also. Way bigger tractor than i need but in my budget, tired of freezing feeding hay at nite thru winter. Question is about the Trans pressure above 1800 Rpm light...... What does it mean?  It comes on if below around 1100 rpm, red lights scare me, i try keep it above that but tractor never sees a load.  just got it and got oil , filters changed today hydraulic may be next.  i dont have a manual that explains this stuff, and did a search on this forum with nothing, prolly did it wrong though, its gotta be a hot topic. thanks for any help

Thanks Steve, i been very worried about it.  No body in my area  has ever ran a  tractor of  this size. Thay think ive lost my mind. 4x5  baler and 10 ft disk mower worst it will see. but i like allis machines, and fits my budget