It is possible to learn how to do this. However, you should realize that graphic design is a design field you need to know quite much more than, PDF template with different styles to begin with.
First you need to know are these PDF files meant for printing. If they are you should spend a few weeks- a few months next to a printer so that you understand how ...
It's possible, but not guaranteed, for your printer to match what your client printed. As you suggested, that the client printed out the RGB file on what is likely a CMYK printer, these colors are likely attainable on the printer's equipment. But the ability to generate these vibrant colors isn't the only thing to consider in the overall problem. Color ...
Two things, Adobe "fit to page" is fitting to print paper dimensions, not the printing dimensions. Printing dimensions are little smaller as there are margins (if you don't override them).
Second thing: try not to use metric and imperial sizes. A4 in inches is translated to 209,97x296,93 mm. And although it's a small thing it might bite you later on.
"Fit to page" will resize the output to fit the maximum printable area allowed by the printer on that paper. It simply scales it up or down depending on the image:paper size proportion.
If you want to print your document in the correct scale (1:1) you need a larger paper (e.g. letter printed on A3) or your document will be cropped (letter on A4 situation).
The only difference is the number stored in the metadata.
This number only recommends the "scale" when you are using a program that actually makes sense of it. These programs are used normally to actually print your document. Think of it as a Post-it saying: "Use this number, please".
It only "recommends" because you can ...
When you are doing artwork which must be fit for both print and web, there is no need to worry too much about the web version. Print files are normally larger than web files (unless it's a very tiny physical format) so if you have a print ready file, you can always downscale it in the end to make a version for web.
Setting up a file for print
As you ...
Paper isn't your only problem, you should also use printing method which can produce rich enough colors which do not get bleak or detoriate otherwise too soon. The paper must be archive quality one without usual color eating chemicals.
People who try to earn money with printed copies of art have about 30 years ago started to call capable enough printing ...
I'd go for canvas rather than paper.
Search "picture on canvas", there are a million places that offer the service, from $£€ 25 for small, thin canvas to 3 or 400 for a 'museum-quality' canvas.
Some services will send you samples of their materials before you commit. Some higher-end services will even print small samples of the very image you want them to ...
First of all, save as .psb not .psd
.psb is capable of more content.
Do not use smart-objects. They will increase your use of memory.
Try to reduce layers, if possible.
Go to the Presets (Ctrl + K):
Don't max out Memory, always keep 20 to 25% as the other apps and the os takes memory too. Taking more will slow down your machine.
Decrease the number of ...
The advice I can give you is, do it the right way.
I am creating a very large high-quality print poster
No, quality is a process, not just a mythical output resolution, and this process needs to analyze the requirements, and the requirements of a wall print are NOT 300PPI.
You will be fine at 100PPI, you will barely notice a pixel at 1 meter, Even at ...