On the problem of soliciting contributions and illustrations
To be honest, there are many people who draw illustrations. Even if the manuscript fee is not high in some places and the review period is short, there are many people competing. If you contact them unilaterally, they may miss your manuscript because they submit too many emails. I suggest you post your pictures on some illustration forums, or post stickers on some magazine forums and leave your contact information so that the right editors can find you.