If you are a hobbiest, your best bet is to befriend a knife maker close to you who has a press who would be willing to share his or her knowledge and press.
You can build one, if you have the skills and tools for $1500 to $2500 depending on how elaborate you want it and how good you are at scrounging parts. Jim Batson, ABS Master smith, put out a manual which is still a ailable and there are some how to build videos on you tube
You can buy one from
https://www.riversidemachine.net/ecommerce/
http://www.mcnabbpresses.com/
There are several other sources, search the internet for "knife forging press price".
Jim A
PS if you fill out your profile with your location, someone might offer to help you.