Hello Kid-lberjack.
Thank you for using Apple Support Communities. It sounds like you're trying to share an entire conversation that is saved in your Messages app. If so, we'd like to share some information with you.
Currently you can select a message or multiple messages within a conversation and forward them. You will have to touch and hold a message or attachment, then tap the More option. This will allow you to select multiple messages or attachments, then you can select the forward button at the bottom right corner of your screen. The following resource has more details:
Send photos, videos, and audio messages on iPhone
You'll want to review the section under "Share, save, print, copy, or delete a message or attachment. This is the only forwarding option that is built-in within the Messages app itself.
You're welcome to leave feedback here: Product Feedback
We hope this information is useful. Best of luck.