Jaybrown

I have a lexmoto Hunter 50cc. It is brand new brought this Christmas so it isn’t old or second hand seems like I have had no end of problems with it. Today I biked out for 10 minutes and pulled over turned my bike off for a few minutes. When I got back on i was trying to start the bike but it wouldent I kept trying then I realised I accidentally flipped the kill switch. I turned that off and I pulled off fine. I was fully reving (throttle restricted) but the bike was going half the speed it usually would. I changed to second gear and the same thing was happening it was extremely sluggish and struggling to move. Every gear I changed to did the same thing. There was no power to the bike i could rev full on every gear and it would be moving the same speed as a fast walk. It was fine a few minutes before I turned it off and went to leave ??? When I rev the engine now it sounds a lot deeper like there’s a deep noise coming from the engine. I would take it to my garage but it’s closed due to covid 19. I’m not good with motorbike parts and how it all works and I don’t see why anything would be clogged or need cleaning when it is brand new. It has plenty of fuel and oil. I wasn’t sure if it was somthing to do with me trying to start the bike with the kill switch on as I have been told them can mess to bike up I’m 16 so I don’t have a car and I care for my Nan so I rely on my bike to get there and back everyday