I usually start off my exercise with 3 sets of around 20 squats. Then I do around 40 sit-ups. Then, I move on to around 25 knee push-ups, then 10 plank push-ups. Then I hit the punching-bad for like 5 minutes, and I finally stretch and stop.
Is this a good exercise routine for losing fat and gaining muscle?
It’s better than nothing. I’d add some way to make it harder, like more sets or more reps. Doesn’t seem like you have access to weights?
No it is not.
Nope. Run through programs off this site. Read 10 Dan John articles and start off with one of his programs
What are your eating habits like?
Not good either.
I mean this part is fine as a weight loss concept. Works at least as well as any other diet, calories considered.
but
Doesn’t sound like you understand what low carb or low sugar means.
Lucas I appreciate it looks like Im quoting things you said, I know these arent your quotes lol.
OP this workout might be ok if you were doing it 7 days a week, but if you are only averaging twice a week you need to be working much harder if you want to see any changes in your body from a muscle building perspective.
Losing weight will be 90% diet, you can likely see changes without changing your workout habits but you will need to be much more diligent on diet.
I had almost the exact same reaction to that in the other thread 
this is not the website for you.
Rowing is great if you gave access to a Concent 2 machine or similar in your gym. I enjoyed 200m intervals with 15/30 seconds rest. X10 reps with x3 sets.