Electronic – Altium Designer Unknown Pin

If you're using ports, you need to (well, really, really, really should) have an upper-level schematic that has all your schematics as sheet entities, and defines the interconnections between each sub-sheet.

Anyways, it sounds like you're looking for the "Synchronize Sheet Entries and Ports" menu option:

_{You can also update each schematic symbol individually by right-clicking on the schematic symbol on the top-level document, and selecting "Synchronize Sheet Entries and Ports" in the menu.}

I'm not entirely sure if this answers what you're asking, as you're describing it in a way I haven't heard before. If you can post the exact content of the project compilation errors, I can probably be more specific.

If you're using schematic ports to connect separate schematics without a upper-level schematic containing each sub-sheet as a schematic symbol and wires to dictate symbol interconnectivity, well... you're doing it wrong. You should be using off-sheet connectors for that (but that's a terrible way to define inter-sheet connectivity anyways).

Edit:

From the OP's comments below, it sounds like the issue is the error checker is complaining that if you have multiple schematic pages with ports specified as "output", that are connected together, this will produce an error. While this error can be very useful, there are many situations where you do want to connect multiple outputs together (Think of multiple SPI slaves. The outputs are tri-stated until CS is asserted).

The generation of interconnection errors are generated by the settings on the "Connection Matrix" page of the "Project Options" dialog. You look for the box at the intersections of the two pin or port types you want to modify the reporting for, and then clicking the box cycles through the possible error or warning generation options.

Making the footprint is generally one of the fastest of all the things you need to do. There are Wizards in Altium that help you make IPC-compliant footprints quickly, and you can set the text height, silk screen line widths and so on to conform to your specific requirements and so your boards have a consistent appearance and set of manufacturing requirements.

Populating the data base with all the things that should be there (vendors, part numbers, alternates, prices, and so on) takes longer. Making a 3D body, if you need to, can take a lot longer depending on your proficiency with 3D parametric modelling software and whether you want to do a good job, a spectacularly good job, or something more slapdash. Here's a rendering of an LED body I did some time ago- the actual die dimensions and position is shown but I didn't bother with the bond wire. The typical library parts often have a crude 3D block or nothing at all.

You only make the part once and you can re-use it thereafter. It's a big hassle to add parts to inventory for the rest of the company, so maybe it will make you think twice about reuse.

Anyway, if you're at the beginner stage (we've all been there) and you just want to get going, use an 0805 resistor and it will be sub-optimal but usable (ignoring the 3D features and such like). You can edit it to show the polarity and save it in a library of your own. You can also download someone else's library that's been done more-or-less properly and (hopefully) learn from that and create your own as you gain experience. IIRC, the 0805 and other Imperial standard footprints may use the metric equivalent numbers (2012 for 0805) as part of their names.