how do i change to config so that new brb civ dont get all the techs i worked hard for like how do i make it that they only get techs that every civ on the map has already?

Change the 'BarbTechFrac' setting in the config file, increase it to give fewer techs ... setting it to 1.0 would do what you ask for, but I'd encourage you not to push it quite that far. Barbcivs will have a very hard time being competitive in the game if they start at the absolute bottom of the pack. Perhaps changing the fraction to 0.7 plus reducing the number of builder bonus techs ('BuilderBonusTechs') to 2 would be a good middle ground.