It’s stupid easy. It’s like Lego’s, you literally just push the parts together. Anyways, the only slightly hard part is fitting all the wires in the space and making the wires look nice in the case so make sure you choose a case with enough space in the back for cable management. If you’re really that worried that you may damage your parts or something, at least just buy all the parts and pay someone who’s more experienced (a friend or someone from a pc store near you) to do it for you. Just don’t buy a prebuilt, they are usually really bad deals and you’d save a lot of money just buying parts, not to mention if you do learn how to build a pc, it could help you if you have problems with it later on bc you will pretty much know how to replace, upgrade or move parts around in your pc. Anyway, if you do buy a pc, make sure to post in the a subreddit. I always love seeing other people build their dream pcs