When talking it's 1-2 seconds, cuz oif it's too long it might look a bit weird as well and you don't want people giving you those looks, cuz that will make you nervous and therefore you'll start to stress out which causes stuttering. However when practicing I'd make longer pause maybe 3-4 seconds, it feels weird but then when you talk to people and make those shorter pauses it feels natural. I also read aloud for 1 hour every day, but again I do it super slowly, so when I'm actually taking my slow speech feel more natural to me.