Hello all, I'm a relatively new plant parent and got myself a FLF about three weeks ago. I just wanted to make sure I'm doing okay because I'm terrified of loosing it

So the plant looks mostly okay but some of the leaves do have these little holes and quite a few leaves have these dark spotting on the top and/or the bottom of the leaf. Also, I've noticed some of them have darker veins than others.





One of the bottom leaves started looking really bad pretty early on and after a while I just snipped it off:



And a few days ago, I notices this spot on one of the leaves sitting at the top of the plant (this section of the leaf was hidden under another leaf if that makes any difference)



I live in Australia in a high rise apartment building and our windows are not very obstructed by other buildings (the next buildings we see are like a block over). I keep the FLF in front of our floor-to-ceiling south facing windows so it doesn't get any direct sunlight but it does look pretty bright. According to the light meter app, this area gets like 380lux at 9am and around 280-380lux at 3pm.



It sits next to a humidifier that's on for most of the day and I water it when the top bit of soil feels dry (about once a week but I wonder if I'm not checking the soil often enough). I haven't been using any fertilizers because I'm not sure which one to get.

I'm just hoping someone could give me any insights on this and let me know if I need to be doing things differently. I do have a bit of a problem with these tiny flies that hang out on my plants but I don't see any white specks on the leaves or anything. But I found this small grey slug in the FLF soil the other day, I got rid of that one but idk if there are more in there and if I need to take more action. Any tips would be greatly appreciated

PS on a happier note, it has put out three new baby leaves!!

Never grown one.

No clue if the dark spots and veins are normal or not. Are they older or younger leaves, maybe it's a maturity thing?
Looks like it might be a woody kind of plant so maybe that's what they do?
I'll let you know if I find anything.

The black spot, I'd guess under-watering.

The white spot worries me, not sure if that something crawling around inside eating it or more likely another watering issue.

Check the leaves daily for a while to catch bugs early.

Otherwise, amazing plants! The monstera looks happy and can I please get some close-ups of that maranta?
That thing is gorgeous!

Ignore the red spots, they happen.
Remove the damaged leaf, it's probably just from shading and maybe shipping.
The "little flies" are fungus gnats, not a threat just a nuisance. Let the surface get just a little drier before watering again. When you water give it a good soak and then let it dry about an inch down before watering again.
Feed with an all-purpose food or not at all, your choice.
The lighting is great although it can take lots more.