About Schengen Visa usage

Guys I have obtained a Schengen Visa from Czech Republic. So my initial plan was to visit Czechia and then Germany, Italy and then go to my home country. I have obtained my visa by presenting this itinerary but if I change my travel plans to North by visiting Czechia, Germany , Amsterdam, France but instead of going back to my home country if I go to UK does it cause any problem in terms of using my visa lawfully. I've obtained my visa too early but I kinda wanted to condense my trip to see more places with an Interrail train ticket but I'm not sure if it would be tolerated. As far as I know if your travel plan has no main destination as in , Interrail, you should be getting your visa from the first country you are entering the Schengen Zone. So what do you think? If I make this changes do I really have to inform consulate about it because I would have to send them all the hotel reservations one week earlier but in Interrail the accomodations are kinda more flexible.