Plant lighting conditions - it's at the top of a bookshelf in the corner between a south and west windows. The south window nearby is blocked by a tightly closed blind and also filtered with a sheer curtain - I know prayer plants don't like direct sunlight. Some brown tips are on the south side, where there is a blind. The west side is all clear however.

Humidity - on average it's around 60-70% on top of the bookshelf. Temperature is between 70 and 80 degrees F. I also put the pot on a bed of pebbles and poured water on the pebbles that would evaporate and keep humidity higher.

Watering: I recently watered it, I made sure it drained well, although the soil is very nice and moist. This is my first plant, though, so I may be missing something, but it doesn't seem to be overwatered or standing in still water.

Again, some leaf tips are brown, but what's weird is that although it's not folding leaves, it's sprouted a couple new shoots just this week. Should I be worried about my plant? What am I doing wrong, if anything? It's my first plant, ever, and I really don't want anything to happen to it.

You're doing everything right..the only issue I see that 'might' be a problem is heat. 80F is a little on the high side.
Aside from direct sun, and lack of humidity, too hot an area can cause brown edges.

If you had more plants I'd suggest running a fan. However, a fan should not be aimed directly on a plant. Rotating fans are best. It helps with air circulation. Is there a window that can be opened in the room?

One more thing to try. Save water in a container. Fill your watering can the night before you plan on watering. Let the water sit 24 hours before giving your Maranta a drink.

Otherwise, your Prayer Plant is doing great. Toni
Ususally, leaves start folding as the day darkens. By chance, is there a light nearby your plant that stays on at night?

I recently noticed, some species don't fold as much as others.
My 2-yr-Maranta 'Lime' doesn't fold its leaves as much as other Marantas.
It's nothing to worry about. As long as your plant is growing, I don't see a problem.

Perhaps, someone else has other information why its leaves aren't closing.

I just got the plant a week and a half ago. Yes, I can definitely open a window in the room and air it out. We live in the city so there is a street light that is outside our window, but it doesn't really give off too much light. I could try closing the blinds for the night and seeing if that makes a difference. I'll also try letting the water sit around before watering. Btw, what does that accomplish - letting it sit for 24 hours?

Thank you for the tips - I'm new to plant growing and any advice helps!

It can't hurt closing the blinds, but if the light isn't shining in your window, it probably won't make much difference.

The good news is your Prayer Plant is growing. BTW, it's best watering in the morning.

Some plants do 'not' like Chlorine. When water sits, Chlorine evaporites.
Spider Plants/Chlorophytums hates Chlorine. More often than not, a Spider, watered from the tap, turns leaf edges brown.
Second reason. It's better watering with room temp water than too cold or hot. Either can cause root shock.

Prayer Plant roots are sensitive, don't like handling. So to keep a Prayer looking its best, a few rules apply. Toni