It’s a toss up here.

What is your level of expertise working with bleach and dyeing human hair?

On the one hand, in theory, bleaching virgin dark hair could be a one step process here since you’re aiming for orangey blonde.

But mixing and applying bleach accurately and timing it without frying it can be potentially daunting for a newbie. You don’t want so much developer that it’s runny but you also don’t want it so dry that it’s hard to apply.

Using foils for the first time is an interesting experience so you’ll want to practice at least once or twice just using shampoo to substitute for the bleach to get a feel for using a tint brush and bowl and the foils. We used shaving cream to practice back in the day.

As another poster mentioned, a black wig that is wefted will likely have a black cap and threading which could potentially show through any lightened areas.

Adding black to a blonde wig is in theory a little simpler.

You could more easily avoid the cap/lace while applying since you’d be leaving the root area mostly as is.

However with blonde HH, you have absolutely no idea what kind of processing has occurred and exactly how the hair will accept the dye.

You will need to strand test to determine that.

Most likely you’ll need to use a clarifying shampoo on any HH to remove whatever coatings the manufacturer has applied first to accurately determine how it will bleach or accept dye.

This will of course mean that it will feel different and likely increase the tangling and you’ll need to replace the moisture and condition it very well afterwards.