Hi Heather
You are correct in learning Hiragana and Katakana first before looking at Kanji. You will need the Hiragana alphabet as the foundation if you are a new to the language. Katakana will be easy to learn once you have memorised Hiragana.
Jumping straight to Kanji without the Hiragana may make it difficult for you. Kanji in a sense isn't an alphabet. There are thousands and thousands of characters which would be difficult to memorise on its own and therefore should be learned as you go along rather than trying to memorise.
Especially as Kanji characters may have different pronunciations depending on the word it forms part of.
Personally I think for the vocabulary it would be best to study the words in both Kanji and Hiragana.
In Kanji - because reading material is less likely to be found in just only Hiragana.
In Hiragana - so that you know how to pronounce the word. But also because some words are written in Hiragana even if they have a version with Kanji (But I think that is preference of the writer).
As you learn you will find that having the Kanji makes it easier to read the Japanese101 pdf lessons among other things etc than if it was all in Hiragana. This is because there are no spaces between each Hiragana spelt word unlike English, so the Kanji included makes it easier to distinguish between each word.
I've probably made that a bit more complicated than it really is…. I'm sorry! Hope someone else could follow up.
