Help! My new Ring of Fire is developing brown spots and crispy edges. Is it sunburn or something else?

Hi everyone! I recently got this Philodendron Ring of Fire and I’m noticing a few different types of browning on the leaves. I’m a bit worried because it seems to be getting worse since I brought it home. I only water when the soil feels dry. The plant also gets indirect sunlight in that spot and maybe 30 mins of direct sunlight. I was told I could wait 2-3 months before repotting with the right soil. I haven't fertilized it yet. I was wondering if I should start to help it "heal," or will that stress it out more? I’m hoping to get some pro-tips from this sub to make sure I’m taking care of it properly.

Thanks for the help!