I don’t think you’ll get much help with this issue in the #help-and-feedback:scripting-support catergory. Try creating a new post in the #help-and-feedback:art-design-support category instead.
Scripting support is aimed at helping people with problems related to programming.
Regardless of that I believe you’ll definitely want to look into a particle emitters :Emit() function for actually displaying your particles. When it comes to styling your particles emitters have numerous properties such as speed, drag, transparency and so on, all of which can be edited using the Roblox properties editor. A detailed list of all properties and their uses can be found at this docs page together with some helpful information on how to get started with using particle emitters:
Information on the :Emit() function of particle emitters can be found on this page:
Also the tool featuring the particle effects you showed in the provided video is actually created by Roblox and you can download it for free using the attached file or using the catalog page if you have a browser extension like BTRoblox installed. I recommend you take a look at how the creators of the tool have set up their particles and maybe mess around with their implementation to get inspired that way.
Ivory-Periastron.rbxmx (76.0 KB)