I was wondering if someone could help with making a modpack?

Hi there, title sums it up pretty well! I’m really new to Java and mods, and a YouTuber named ‘Snifferish’ has a magic play through with their mods listed in the description. I tried to add them myself but got a bit confused with some of the mods. I did a bit more research and found someone who had made a modpack based on this playthrough, but it had 300+ mods and kept crashing my game! So I was hoping could someone maybe be able to help me create an exact modpack of this play through? Or maybe let me know how I could fix the crashing? The description said to increase allocated RAM, which I did, but that didn’t work. Any help is appreciated, thank you!!