I wanna make videos on allen bradley plcs. And maybe a future video on fanuc robots. Is this some thing i need permission on? I wanna make videos to help others learn and troubleshoot but don't wanna get sued in the process.
I don't think anyone here is qualified to give you legal advice. But I'll share what little I know on the subject.
Generally speaking, using someone else's trademark in your course title isn't OK without permission. Some companies have their own training businesses or license out the rights to do training on their products, and don't take kindly to people developing their own courses without a license. Sometimes that just ends with Udemy receiving a demand to take down your course, but worse outcomes are possible.
Some companies publish usage guidelines for their trademarks, but I couldn't find any for the two companies you listed. The safest course of action would be to write to them seeking written permission to do what you want, and to consult with a lawyer who can better inform you about the risks you're taking by doing this.