Jahee,
You are very much the same as me. 
I don’t like to waste anything either. So I found something on craigslist.org, very cheap. This generator is from the 1950s or 60s. The company that made it still exists, but they will not sell me a manual or even talk to me about it because it is “more than 30 years old”.
But this is the best machine for my me. Even though I do not have a manual I was able to take it apart, clean everything, put it back together, and it still works. It is very simple, makes a lot of noise, is not efficient, but it is very durable. I think none will steal it, because it is not as we say, cool. But I can LEARN everything from this machine. After I have learned as much as possible, then I will get something better. This is my approach.
Rindert
My generator is 8000 Watt start up and 6500 W. running. It runs that little welder on either 120V or 240V on gasoline or propane with no problem. I’ve never put a watt meter on it to see what it’s actually putting out on gas. At 240V it will run a Hobart buzz box welder but with a short duty cycle before it kicks the breaker. The generator has a 30 amp fuse on 240V and really needs a 40 amp to run that welder. I have never tried to switch from propane to chargas yet. I’m guessing that will be easier than gasoline. I will never buy another generator without an electric starter.
Smart device, @r_wesseling. Especially this tall gasifier looks pretty cool and simple. Did you share its construction here already?
Kamil,
This gasifier is not ideal, too small. It is only for charcoal. But it works. It is based on @k_vanlooken designs in Thailand. There is one only critical dimension, it must have at least 600mm of charcoal inside or it will not work. I think most people can make something like this.
Rindert
Hardly ever seen such essence of KISS principle before.
Kamil,
Check out Gary Gilmore’s Simple Fire for the original design of the above system. I have built three–one to run a lawn mower, one for a grist mill or generator, and the largest powers my Toyota Corolla. There are many example builds on this website.
Yes. This is a very good first project because you cannot fail.
Rindert