CBD-Öl

I use an Instapot to make THC extracts. It does both the decarboxylation as well as cooking into your binding agent (butter, cooking oil, etc). As mentioned by @m0use, you need to start with a high CBD cultivar. If you don't want THC, you'll have to start with a cultivar that is CBD-only. Then, as mentioned by @Green_claws, watch YouTube videos on making the extracts, oils, etc. There are a lot of recipes, but it all depends on your equipment. It's not difficult.

if your POT has high CBD then you can try extracting it in any fat/oil. Many methods most home done stuff is going to be a bit harsh as its not a lab and extracting just the CBD. If the POT you are using is kinda bunk. then the product will be a bit bunk. you can't have magical results from nothing. Good suggestion about decarboxylation, this makes the POT more active. Most of the CBD in the plant is classified as CBD-A that "-a" makes it harder for the body to use and you remove it by apply heat over time. Their are other ways of removing it but that is the simplest for most people. If it has THC in it, that THC will be extracted with the CBD. Use buds only, using sugar leaves and stuff will give the oil a green taste and even colour sometimes. Some method for extraction I ave used in the past is a slow cooker or baby bottle warmer/steamer controlled temps over time, no burning. You just need enough oil to cover the ground bud. Filtering it out can be tricky, some like to place it in tea bags and squeeze em. Just make sure they can take the heat.

Oil for what mate. Make sure you decarboxolate for stronger outcome.. that's all I know know really pal. That's my 2p worth for you. Loads about on google Hope this helps.