its fairly simple to look up the following details which are important when purchasing a new computer. For modern day use especially browsing the CPU needs to be 4 Core minimum and the Fitted Ram needs to be 8GB minimum, note: you are probably losing 1.7GB of your system RAM to the Intel HD graphics integrated GPU. You should confirm the CPU speed benchmark for single thread and for overall multi core operation. By looking up the CPU on the Intel ARK you find out specs for it. Check the specs of an intel CPU using the Intel ARK your 6100u can be found here https://ark.intel.com/content/www/us/en/ark/produc… and from that information we can see its stumbling block is its only 2 core . If you now click on the Range(skylake in this case) you can see your cpu against the specs of the others in the same range. Only a subset of these cpu’s can be fitted as an upgrade and its probably not worth it anyway.
The Benchmark for your cpu Single thread 1349 (quite poor) Multi core overall 2610 (reasonable)@ 15 watts so thats a save battery type of CPU found here https://www.cpubenchmark.net/cpu.php?cpu=Intel+Cor… To be a good laptop these days your target should be Single Thread 2200 and multi core overall 8000. A typical example being an i5 9300H which is 45 watts found here https://www.cpubenchmark.net/cpu.php?cpu=Intel+Cor… This gives a very good single thread score of 2390 but an excellent overall of 7919 which is where the real performance is found. As a general rule the wattages determine if its a save battery type of CPU or more of a performance CPU.
So go get a min 4-core cpu with a benchmark of more than 2000 single thread and 8000 overall, hope that helps.
Game play is something else and only a 2nd dedicated GPU will really help you there, and the 6100u has an Intel HD 520 integrated GPU(part of the CPU) and therefore shares part of your 4GB or RAM, which reduces your system performance immensely because as I stated above a system needs at least 8GB or Ram these days sharing as little as possible to keep overall System performance up. Something like this one https://www.box.co.uk/FX505GT-BQ008T-ASUS-TUF-Gami… is about as cheap as you can get a reasonable gaming laptop i5 9300H -Ok Solid state disk – nice Dedicated GeForce GTX 1650 4GB Graphics 2nd GPU reasonable for a cheap Gaming Laptop especially with its own 4GB VRAM.