Hey. I actually ended up having to this the hard way before the "Export Profile" feature was introduced. That has since been added to the CurseForge client and all of this is now MUCH easier. I'll walk you through what you need to go since it's not really documented anywhere what the full process is.
I'm going to make this guide assuming you know the basics of modpack creation and basic usage of the CurseForge client.
1. Create your modpack on the CurseForge client by hitting the + Create Custom Profile button in the top right.
Give the profile a name and and select a Minecraft version and Forge version. The current "gold standard" for fully-featured modpacks is Minecraft 1.12.2. The forge version I recommend with this version is forge-184.108.40.20647.
2. Click the Add More Content button and install all of the mods you want. Do some research on this as many of the big modpacks have dozens of mods that just tweak small things that provide huge quality of life improvements.
3. Fix and incompatibilities. Sometimes there are dependency mods/libraries missing. Most of these should be downloaded automatically, but some are missed. Most of these issues won't be seen until you launch the modpack, so make sure all of those kinks are worked out.
4. To export the profile (which will be used upload to a project here on the CurseForge website to make your modpack public), select the 3 dots next to play and select Export Profile.
5. In the Export Profile options, Enter the Profile Name, give the package a version and make sure config and mods are selected and click Export and save the profile to a location you will remember. The default location is .\Curse\Minecraft\Instances\ (.\ is where you installed CurseForge).
6. Start your project by clicking here: Start YourProject. Fill out all required information. At some point, you'll be asked to upload a file for the modpack. That's where you upload the .zip of your profile export you did in Step 5.
7. You will need to provide quite a bit of information to get the project approved. If you want an example project description, here is mine that is approved. If its denied, they will give you a reason and you must fix it before it's approved. After it's approved, it'll show up in the CurseForge launcher within a few hours. Once it's in the CurseForge launcher, any hosting site that pulls from CurseForge modpacks will be able to see it.
I hope all of this helps! If you need more help, the CurseForge Discord Server is super helpful, specifically the #curseforge-questions and #community-support channels.
what i want to know is how in the world do you find the errors becuase often i lunch the pack im currently working on (its still a more just me for now) and the lunch fails and i geat a error message with a 0 so any palces to look?