In our salon l&P still rules but only just these days. We do whatever we get asked to do or the clients have whatever we advise them to do (what a client asks for is not always what is the best choice for them) and you need to learn to do ALL systems well. You can't be a complete nail technician and offer only one choice.
My advice if you are just starting out is, that I'd go for L&P and a UV colour coat to start with and then move on to hard gel.
Learning L&P first teaches you complete control of your brush and it teaches you how to structure a nail enhancement so that it lasts (at least a good course will teach you that).
Learning to apply a UV colour cost will teach you how to polish a nail and give you instant business while you are perfecting your enhancement skills.
Get the very best training you can afford is another very important piece of adivice. Good luck.