My questions are
We have a strict "
one issue per thread" policy that you agreed to respect when signing up. You have been told about our policies (i.e.
board rules) before, please read them and respect them from now on; you have broken them several times already. Posting several questions in one thread is bad, and especially generic posting generic questions that are not directly related to the user-contributed bridge discussed in this thread, but that are generally about bridging. Your questions show you haven't read the docs nor have you understood the bridging concept.
2.2.6 Consider bridging
Coppermine was designed to be used as standalone application in the first place. However, many people wanted to integrate it with another app, so starting with cpg1.1.x coppermine came with a mechanism that allowed users to bridge coppermine with another app in terms of user management. The main advantage is giving your site visitors a single sign-on for your overall site (e.g. both in your gallery and your forum), so they don't have to sign in twice and memorize two different logons.
Bridging does not integrate coppermine visually into your home page (you have to create a custom theme to accomplish this).
You can enable (or disable) bridging at any time, but you should make up your mind on bridging when installing Coppermine in the first place, because there are some issues that have to be taken into account: if you already have users inside your coppermine database when enabling bridging, the correlation between those initial coppermine users and the "new" users from the app you bridge with gets lost. As a consequence, there will be no more correlation between things your "old" users did (uploading pic, posting comments etc.) and the "new" users from the bridge.
To circumvent those future issues, you should make up your mind when installing coppermine: do you want to allow user interaction? Do you plan to offer a bulletin board later (or any other application that keeps track of users)? If your answer is "yes", or "maybe", then it's advisable to enable bridging before actually promoting your site publicly and starting to let users in.
Read up details in the bridging section of the docs.
1- I have installed coppermine in my main folder mygallery.com, do i need to move the gallery in subfolder ore i can install joomla in subfolder and make the integration ?
Both options possible. Your choice.
I want when i open the link to my domain mysite.com to open joomla with link in the menu to the gallery?? Is that possible ore not ?
I don't understand the question. However, I doubt that you own the domain "mysite.com" - that domain is owned by a webhosting company as far as I can see. You mustn't post dummy placeholder links, but real life links, as per board rules. Yes, you have been told about board rules several times already. Why do we have to repeat that again and again?
2- Do my users from the gallery automatically get the accounts for Joomla after that ?
No, the opposite is the case, see
5.2.3 Coppermine users, groups and pics uploaded by users are lost when integrating
Warning: If you already have users and custom groups in your coppermine database when you enable bbs integration, be aware that they will be lost. If your coppermine users have already created private albums and uploaded pics to them, they will be lost as well!
3- I have phpbb3 installed in subfolder too. I didn't make bridge for it with coppermine, can i make the bridge after that too ?
No, of course not. Coppermine can only be bridged with one application that then becomes the master. However, phpbb maybe can be bridged with Joomla as well, or maybe there is a particular phpBB-port for Joomla available, who knows?
What you ask is generic bridging advice. Stay out of this thread and do as suggested. If you have actual individual bridging questions, start a thread of your own, respecting board rules and reading the docs before doing so.