45-Piece Crayola Signature Crayoligraphy Hand Lettering Art Set Expired

Get a fountain pen and a 4-line notebook like this https://files.suryascursive.com/w...ksheet.pdf
I don't think ball-point/felt/gel are good for this.
Never too late to fix your handwriting. In India, we ruin our handwriting taking public exams (board exams) because we have to write a lot. Our Class 11/12 English teacher took the first 10 mins of every class trying to rectify this. Kinda worked on me.
Now, after years of typing, i can't even chicken-scribble for 30 minutes without excruciating pain. Such is life.

If you're mostly interested in improving your handwriting (vs. learning handlettering), I would suggest that you take a different approach. This kit is more about learning modern calligraphy/handlettering, and that's all about learning the techniques, practicing drawing the letters, then learning to flourish on that.

To improve handwriting, try this: Start by taking a look at how you hold your pen and the pressure you use. I find many people grip the pen too tightly and push too hard. That adds to hand fatigue and makes it hard to make smooth motions. When you try harder, you are likely moving more slowly and intentionally, which counterintuitively makes it worse because you are introducing trembling and tiny corrections along the way (I put an exercise at the end to illustrate that). Handwriting is all muscle memory. The only way to improve is practice.

"bad" handwriting can usually be summarized in just a few problem areas: poor or inconsistently formed letters and inconsistent spacing or letter size. The rest is preference on style.

Take a look at your handwriting in terms of those things and pick the thing that you like the least. Then just focus on improving that one thing. But it must be intentional. Whenever you can take the time to do it, work on that one thing. It will make you slower at first, and it might make your letters uglier at first. But stick to it and you should see improvement.

For example, if consistent letter size is the problem, focus on that. You'll probably write slower. That will probably make your letters more lumpy. But eventually, you'll internalize what it feels like to hit the same heights and you won't have to think about it anymore, you'll do it naturally. Then your speed and smoothness will return.

Try this exercise: draw two dots on a piece of paper about the length of your pen apart. Now connect those dots slowly, trying to make the line as straight as possible. Next do it again but do it more instinctively and confidently. Just draw the line. What happened?

Most likely the second line is much straighter, but there's probably an arc to it and you missed the second dot. Do it 5 more times. You'll improve over time. You can try to do a similar exercise with circles: make a square and carefully draw a circle inside. Now try to smoothly and confidently do it... Writing is basically all lines and circles...