Creating custom score

I don't know which MuseScore version you are using. I can give a tutorial for MuS 3, but it should be quite similar to the newer version.
The first step is to read the manual chapters (MuS 4), starting with https://musescore.org/en/handbook/4/basics for example.

Basically the order is as follows:
Open Musescore, File / New, choose the instruments and sort their order, choose the key signature, time signature, tempo and number of measures, and whether a pickup measure is needed or not. More or less measures can be easily selected later (Add / Measures or Tools / Remove empty trailing measures) and all other settings too.

For more questions, consult the complete manual, where you will find almost all the answers that will come up.
https://musescore.org/en/handbook/4/full-table-contents

Manuals are also available for older MuS versions.

Whether you have paid for a subscription to the Musescore.com score sharing service has no bearing on using the free Musescore notation editing software. It also has no bearing on the support you may or may not receive via this forum in which users of Musescore provide help to each other as their time, inclination and knowledge permits.

I gave an answer to your previous post asking a similar question here https://musescore.org/en/node/354376#comment-1206757 If that did nor provide sufficient help, it would probably have been better to reply to that answer describing why it was not sufficient and providing more detail about what you are trying to achieve. But here we are in your new post and so I will attempt again to address your question:

You say templates do not work for you. Do you mean that there is something about using templates that does not meet your requirements - if so, please describe in more detail what your requirements are; or do you mean that they may meet your requirements but you are having trouble with creating or using custom templates of your own - if so, please describe in more detail at what step in the process you are running into difficulties.