Hey there. In my personal opinion, starting with hira and katakana is a good begining. Then you should start learning some vocabulary first.

For example you learn 10 words and how they are written in hiragana or katakana/depending on the word/ and only then learn the kanji for these words.

Kanji is like a little picture so if you look at it for long time, write it a few times soon you will remember it. Also if you read this kanji in a certain sentance you'll be able to recognise it faster and finally memorise it for long time.

I can also remind you that Japanese is consisted of 5 levels.

N5 - 100 kanji and around 800 words (about 150 hours of studying)
N4 - 300 kanji and arond 1500 words (about 300 hours of studying)
N3 - not specified but it is between levels N4 and N2
N2 - 1000 kanji and around 6000 words (about 600 hours of studying)
N1 - 2000 kanji and around 10 000 words (about 900 hours of studying )

I think N5 is elementary level
N4 - pre-intermediate
N3 - intermediate
N2 - advanced
N1 - proficiency

I hope I have helped! Ganbatte!