This is my first time building a PC. I spend a lot of time researching about PC parts and most importantly the price of each component. I compared the components many times with amazonDE and my local market. I will suggest you to do the same. Also be sure that everything is compatible. Noting is worse than buying a new PC for the first time and finding out that some parts doesn't fit. The satisfaction of building your own PC is amazing. All though it's hard when you're building for the first time and require patience, it is very great when you're done. Make sure to not rush things though, since your components are very delicate and require slow movements when moving them in your case.
I'm going to use the pc for university and gaming(=dota2, overwatch, cs;go, hon etc.)
CPU: I got a cheap intel pentium g4560 which I bought in my local market in my country.
Motherboard: I got this for a good price at amazonDE.
RAM: I just found the cheapest I could get. Also getting 1x8gb is great since I can upgrade by buying another 1x8gb in the future. Be sure though to buy the same one.
Storage: I got a good price on SSD from amazonDE. I don't need much storage since I don't download lots movies, photos, video format etc. 240gb is enough and if I need more in 6-12months then I will just get a 1tb HDD.
GPU: I got this for a very good price in my local market. I watched plenty of benchmarks with intel g4560 + gtx1050ti and I saw very positive results.
Case: Just found a cheap one on amazonDE. Also make sure to watch a review of the case on youtube, so you know what you're getting.
PSU: I got a 500w PSU for a good price in my local market. I recommend to never go below 500w. In my case I might upgrade CPU to i5 in 2-4 years. So spending some extra on a good PSU will save me a lot when I upgrade.
Monitor: I got a 21' monitor from amazonDE. It was on sale and 21' is plenty for me so I just bought it.
Make sure to watch reviews on youtube, so you know how the components look.
My biggest headache when building my first PC was connecting the front panel to the motherboard.