Recently bought an LG fridge but when I plugged it on at home it was just hot not cold what can I do

Power off and remove all fluff under the fridge.
Compressor can be hot but not too hot. Are the settings ok for desired level cold. Is the fridge too heavily loaded? Try now.

Check the condenser grille on the back is clean and warm to the touch. It should cool down towards the bottom and the drier cooler still. If it's cold, suspect short of refrigerant. If it's hot, move the fridge away from the wall to help it cool down.

You will need to check the evaporator it may be iced up. Two things may cause this the evaporator fan motor may be bad or the condensate drain could be clogged and causing the water to freeze on the evaporator. When the evaporator gets iced the air can't pass over it and get cold.

Feel the motor temp. after letting it do its thing for a reasonable period. If motor is extreemly hot then it means motor is switching off on internal protection.(has to be replaced then.). Set temp to its coldest then see if it still switches off as it is. if the same, board is more likely to be a problem. Very seldom if ever does one have to replave sensors. (assuming it has an electronic board). If using a th/stat, replace it if temp does improve but still eratic.

Firstly, the thermostats are usually calibrated at one elevation and where the fridge ends up may be above or below that so the number settings on the dial aren't that relevant. You should adjust the thermostat in increments then check the temperature after 24 hours, then adjust again if necessary. The fridge should be as close to 40 degrees F. as possible and the freezer about 26 degrees F. (if memory serves me). The heat you detected is the unit in defrost cycle and should be considered normal if intermittent and a problem if constant. There should be a switch to turn off and on the defrost feature if you determine it's a problem.
I hope this helps you and good luck.

Sounds like the freezer fan(FF)is wearing out, This problem is very hard to diagnose because the fan spins but not fast enough to circulate the chilled air thru the freezer and refrigerator. This repair costs parts and labor around $300.00

I have bought this fridge yesterday all plugged in working well got nice cold water but its not filling the ice try inside to make ice? Dont know why

Hit it with a big stick!

If the fan inside the freezer is running and the compressor behind the fridge is running and is hot to touch, you have a gas problem or the compressor is inefficient. This can only be confirmed by connecting refrigeration gauges to the gas system and should only be performed by a fridge tech.