There are lots of free legal forms online and in print, but none of them will be the exact forms you need in your specific case. You can lose a lot of time and money if you file the wrong forms.
Courts are very, very careful when it comes to child custody legal matters. Oregon courts do not have official or fill-in-the-blank child custody legal forms for parents, grandparents, or for any third party seeking child custody. You need to draft your own forms specific to your legal situation.
There is a useful booklet you can read for some background information on this subject. Link to the booklet from this blog post:
If you want to represent yourself in your case, you will have to research the laws and the regulations about child custody and third-party rights and then you will have to prepare your case. You will need to do this research in a law library. You can find a list of Oregon county law libraries at the Oregon Council of County Law Libraries (OCCLL) website.
You can also ask a lawyer to serve as a “coach.” Find a lawyer who will review your situation. Explain that you want to proceed as a self-represented litigant and ask if the lawyer would be willing to serve as a “coach” to help you through the legal process. (This is also known as “limited scope legal assistance.” You and your lawyer will sign an agreement that limits the scope of the lawyer-client engagement and legal liability.)
You can also ask a lawyer to represent you in a custody case. The lawyer will give you an analysis of the likelihood of you prevailing in your case and give you an estimate of what it will cost.
The Oregon State Bar Information and Referral Service has a toll free number to call to get names of attorneys in your area; call their referral service at 503-684-3763 or 1-800-452-7636 or visit their website.