after looking at some google, I realised that I can combine multiple internet connection to boost my one computer internet speed. But problem is that I don't have multiple device to connect to my pc. Is there another way of doing it? It of course needs to be done at ubuntu( i have ubuntu pc, in case if you are wondering, i have intel i7 6700k and gtx 1070 with 16gb ddr4 hyperx fury black, and msi h110m gaming motherboard. Plus, sum amazing be quiet cpu cooler with amazing corsair bronze 600w power supply. My case is xpredator x3 devil red with 2 custom fans. I get about 800 fps in minecraft, max settings.) After doing this, I can play minecraft multiplayer without LAG!! YAYAYAYAYAYAYAY
Ok, allow me to boil this down for you.
Can you combine internet connections to increase overall connection speed?
Yes, this is called Link Aggregation
Will these extra connections allow me to play games with less latency (lag)?
In most cases, probably not
Becuase you are probably experiencing lag due to your ISP (Internet Service Provider) not providing you with enough bandwidth (data speed) or bandwidth latency (lag) to allow you to play with little lag. Combining internet connections on your local network will only increase your speed to the other devices on your network. Not the outside world. There are systems that would technically allow you to combine two outside internet connections to achieve this, but it's not as simple as plugging two cables in.
What should I do?
You should get in touch with your ISP and find out how much bandwidth you are paying for, then you should go to Speedtest.net and run a test to see how much you are getting out of the box. (So plug right into your modem) If for any reason you are not getting the speed you are paying for, there is a problem and you may need to have a technician come out and check things. But if you are getting what you pay for, then the only solution for you is to pay for more bandwidth. Sorry, but that's just how it works.