Sounds to me as if you need to spend some more trigger time on various platforms before you make up your mind what you want to put _your_ money down on. Lots of differences in 'feel' and manual of arms between pumps and semis, lots of different makes/models of each that are worth considering. Talk to your friends and acquaintances, buy some practice ammo (light loads of birdshot will do for most) and see if you can get invited for some range time with different platforms. 'Job 1' is to decide what it is that you want for the task(s) you have in mind, best to think through what you want the gun to do for you as part of deciding what to get.
Reliability between pumps and semis these days is hardly a factor given good ammo and proper maintenance. A pump is a bit more versatile in that it will handle light loads the semi chokes on, if that is a consideration. There is not really much else to differentiate between pumps and semiautos save cost, and that is apt to be a considerable diference. Semiautos are likely to cost twice as much or more than pumps.
If you are getting a shotgun with the intent of actually learning to shoot it, I suggest starting out with a 'stock' or plain jane version of whatever you decide you like. Spend your money on ammo early along rather than accessories and shoot that sucker until it handles like it is part of you. Then start working on making it into what you want, once you have an appreciation for the feel and handling characteristics of the basic gun. You will be more able to add things to the gun that help it perform better for _you_ at that point, rather than working off some arbitrary list of what a properly accessorized shotgun is s'pozed to wear this season.
Note that I have nothing against accessories on guns. I just like for bolt-ons to add functionality rather than detract from it. And I do not believe it is possible to buy skill and ability in boxes and blister packs and bolt it onto a gun, that takes time and practice and there are no shortcuts. Some things CAN help a shooter perform better. Some are like many fishing lures, more designed to catch fishermen than fish.
Good luck with the project, have fun and stay safe,