Help with counting Macros

Counting macros and counting calories (while pursuing well-rounded nutrition) amount to just about the same thing: Each macronutrient has a characteristic average calorie level, so things work out about the same. (Protein and carbs have roughly 4 calories per gram, fat has roughly 9 calories per gram, alcohol - not exactly a macro, but a thing with calories that's not one of the other macros - has 7 calories per gram.)

So, if you set up MFP, get a calorie goal, and strive to come close to the default macro goals it gives you, that's approximately the same result as counting macros (ignoring some minor rounding error).

Zig-zagging is an optional thing. It's worth doing if it helps you stick with a calorie goal, otherwise it's a needless complication for most people, IMO.

If you follow the standard MFP approach, you would set your calorie goal based on daily life before exercise, and log exercise calories separately on days you do intentional exercise (or synch a fitness tracker to do that math for you). That results in a loose form of zig-zagging, because you'd eat different numbers of calories on different days.

Another possibility is more lifestyle based, i.e., some people like to eat fewer calories on weekdays, then more on weekends, or some variation on that theme. Free MFP won't track that for you at the detail level, but you can either do it by managing to your averaged weekly calories (viewable in the phone/tablet apps), or more explicitly plan it day by day with premium MFP.

Beyond that, there are various web sites that suggest different zig-zagging schemes for different goals. I can't comment more specifically than that, because I don't do that. (I log exercise separately the MFP way, plus calorie bank, i.e., eat a little under goal most days but not dramatically low, in order to indulge a bit occasionally, balancing out around the right average level. I've used MFP more or less that way through a bit less than a year of losing 50+ pounds back in 2015-16, and 5+ years of maintaining a healthy weight since.)

Best wishes!

You might wish to join this group:

https://community.myfitnesspal.com/en/group/394-low-carber-daily-forum