Welcome to the ILGM forum @Shewy12, you will get all of the help you need here.
There seems to be as many opinions on pruning and defoliation as there are growers.
That said, I am of the school of thought that if the plant is getting enough ventilation and air flow through the lower canopy, I don’t remove any material. As @garrigan62 points out, the leaves are the chemical factory that uses sun light to convert nutrients into the things that the plants need to grow and ultimately flower. After a few weeks in flower I do remove a few of the lower branches that are not developing very well.
About two weeks or so before harvest I start gradually removing fan leaves so that the fan leaves are nearly gone by the last week before harvest.
This is just my 2-cents worth, and I am a new grower as well.