if you are seeing only pressure as available load options, you are probably using the “static analysis” and not “static analysis - advanced” analysis type - its there for historical reasons and will be removed soon. Changing to the “advanced” solver will make many new load types available. See this post for further information.
Regarding the problem with not connected parts: If you have a multi-part assembly you have to connect those parts using Contacts or Physical Contacts such that they can transfer forces between each other. You do not need to fuse multiple parts, but it is a good practice to get a first simple version of the analysis going and then gradually reaplce those fused parts with more physically correct connections, if needed. For more information releated to the different contact models you can have a look at our documentation: