Fallout 76 perk cards can be swapped in and out whenever you feel like it—meaning you can temporarily get rid of that boost to explosive damage in favor of a +1 to hacking the moment you need to crack a computer, then go back to being a combat machine afterward. However, there's no way to respec choices you've made (yet) regarding which stat to increase, or which perk cards to upgrade. That's why, if you're going to get serious about specializing with your S.P.E.C.I.A.L. stats, it's a good idea to tinker around with a character build planner before diving in. It's also a good way to help kill time until Fallout 76's November 14 launch.
There are a few build planners online but the most aesthetically pleasing and easy to use is You Are S.P.E.C.I.A.L. by Nukes & Dragons. It handily calculates the effects stat increases have on your carry weight, hit points, and action points—each increase in Agility is 10 more action points and each increase in Endurance is five more hit points, while every increase in Strength means five more pounds of dog food and bullets you can carry.
It also has a searchable database of all the perk cards currently known to exist, including some found by dataminers that haven't been confirmed to be part of the final game yet like Lavish Lender, which increases the time you're allowed to share perk cards with teammates by 25%.
While perk packs hand out cards at random, at each level-up you also get to either choose one new card or have the option to upgrade an existing one, so there's definitely utility in making plans for a build in advance. Whether you want to go hard on the likes of Gladiator and Martial Artist to make a melee heavy-hitter, or E.M.T and Injector to heal your friends, or just combine all the liquor-related perks and roleplay being a drunk, there's something for everyone.