Tank cycle help !

Hey guys I?m new to this site so not really sure where I should be posting.

So I?m currently cycling a aqua nano 40 It?s a 51L ( 14g ) fresh water tank that I have converted to a salt water system, I have only just got back into the hobby after a year break, anyway I have always had a saltwater system but I have never had to cycle a tank before as I bought my last tank already fully established, so I have a few questions if anyone could help would be fantastic !

It is a fish less cycle with my old live rock that has been soaked and air dried, I am using black live sand I am 4 weeks into the cycle and I?ve just started running the skimmer, I have been testing weekly with salifert test kits but I haven?t wrote down the results (silly me), I started the cycle using stability and feeding the tank fish flakes. Just a few questions

I never really had a ammonia spike but did show a little Ammonia on the chart it is now down to 0ppm but I am now showing very high nitrite and nitrate, so does Ammonia need to spike before nitrite and nitrate starts to show ?

Have I had my ammonia spike for nitrite to be showing on my test ?

Should I still be feeding the tank every single day ?
Has my cycle stalled ?

Should I do a water change ?

Or should I just let it run it?s course ?

I am so confused so if you could tell me in detail that would be fantastic !!

I still consider myself a newbie even though I have had tanks in the past thank you for your time !