When is the best time to start sleep training?

Hi! I’m a first time mum and super new to all of this and it’s so overwhelming how much information there is to know😩 My little boy is 11 weeks (12 weeks on Thursday), is it a good time to sleep train now or is it too early? What are your best tips and tricks please? He’s not too bad throughout the night, although he has been abit hit and miss the last week or so with his night sleep, not sure if this is a regression or anything at this age? But he usually wakes up 2-3 times a night but I’d love to start getting longer stretches of sleep from him.. we had 1 night where he slept 10 hours straight and I was in utter shock but he’s not done that since