If you want to use the ATLauncher, I've just released ShneekeyCraft for 1.12.2, which is a lite pack designed for people new to modded minecraft. It doesn't have all the bells and whistles a 'full' pack has, but it has enough to get you started with some of the concepts involved in modded minecraft.
It also has some 'optional' mods, which can enhance your experience. I would advise starting a new world when adding in optional mods as most of them require additional worldgen which will not be present in any explored chunks. Also, under optional mods, there is both Refined Storage and Applied Energistics 2, however they are mutually exclusive, the launcher should only permit you one or the other. They both do the same thing, which is inventory management on a large scale and auto-crafting including subcombine autocrafting, but Refined Storage is more simplistic in nature, while Applied Energistics 2 has more to learn and enjoy, and in general is a better puzzle to solve. If you just want something that will handle the problem, go with Refined Storage. If you want complexity and puzzle-solving, go with Applied Energistics.
The oregen will be mostly 'vanilla', while I was playing around with a significantly altered oregen using CoFH World, ultimately I decided against it because it would be more difficult for players new to the modded experience to understand. There will be a few new ores to mine, but it should be relatively straightforward.
In virtually every 'lite' or 'newbie friendly' pack, there is generally a mod called 'Tinker's Construct', which can be used to create tools using an entirely new mechanic that I highly suggest, right from the start. Putting together Tinker's Construct requires little more than wood, and you can avoid making a single vanilla tool if you wish. Tinker's Construct tools can be repaired (i.e. they don't get destroyed when they hit zero durability) and upgraded (by crafting it with the appropriate new part you want on your tool in the mod-specific bench) as well as Augmented (basically an enchantment mechanic which uses resources to produce defined enchantment properties instead of leaving you at the whims of RNGesus).
i've been playing minecraft for almost 7 years now but i have never acutally played with mods can anyone recommend a good beginner friendly mod pack to learn and enjoy it ? : )
