Surely there are local sellers in Europe!

If you are serious about electronics as a hobby, you will eventually buy a bunch of resistors, capacitors and other parts to have in stock. Resistor kits can be had on Ebay for a few bucks that have all the values you will ever need. I am a software engineer and electronics hobbyist and I keep a complete stock of all E12 resistors 1Ω through 10M in through-hole and two sizes of SMT. Also 1W ones for lower values. I literally have 1000s of resistors, with the total cost being less than $50.

Bob

 

and to drop from 12V to 1.0V(for transistors bases)

If you are putting 1V on a transistor base, it is no wonder things are blowing out! That voltage should rarely be above 0.7V. The highest value characterized in the 2n3904 datasheet is 0.95V.

Learn how to calculate resistors for both LED and and bases (which is basically the same).

Bob

 

To deliver something from US to Europe it takes months. I remember I bought something from ebay and it took 2 months and I had to pay vamal taxes

These days I wouldn't buy many electronic components from eBay. You're likely to get counterfeits or some cheap knock offs. Similar for Amazon, Ali Express, etc. Stick with known distributors like Mouser, Newark, Jameco, Digikey, Tayda, etc.

 

I have never gotten a counterfeit anything buying from Amazon or Ebay. So, in my experience it is not likely. I would like to know how one makes money by counterfeiting resistors and selling them for a fraction of a cent, though.

I think the counterfeits are likely only found in difficult to find parts that cost several dollars or more each. Here, they simply take another one the same package and change the markings.

Bob

 

I bought a counterfeit BMW ignition switch from Amazon, complete with BMW logo. I didn't return it because I didn't feel like taking my steering column apart again.

 

It's a shame Amazon and eBay get a bad rap...because it's really the dealers that sell this crap. If you know who to trust there is no problem using these market places.

 

How can I add a resistor from the transistor base to emitter? Does that mean the resistors of the 2 inputs A and B from the following image?

No. That is nothing at all like what I described.

Here is a quickie schematic based on your schematic in post #6. As you can see, there is one resistor from each transistor's base to its emitter. This provides a shunt path for collector-base leakage current that can keep a transistor conducting with an open base and a low load current. You don't have any component values, so I made up some. Note that R3 is zero ohms. I show it in the same place as on your schematic, but it can be eliminated from the design. Base current limiting is not needed because you are operating the transistors as emitter followers rather than as saturated switches.

ak

 

The last question is how to measure the voltage

I have this multimeter:

I set it to DC voltage measure, the question is where to put the red wire and black wire on the circuit to read the voltage after the resistor dropped some volts?

 

The last question is how to measure the voltage
View attachment 251024
I have this multimeter:
View attachment 251025
I set it to DC voltage measure, the question is where to put the red wire and black wire on the circuit to read the voltage after the resistor dropped some volts?

There are three different components. Place the leads across each component in turn in any way you choose. Try it two or three different ways. Pay attention to the signs associated with the readings, Try to find a way where a rise in voltage is negative and a drop in voltage is positive. When you find that situation, add all there values together and see if the result is pretty close to zero.

 

View attachment 251021

This is not a good circuit -
If it were an AND gate, then with SW1 open and SW2 closed then LED should be OFF.
But the LED will be ON because of the current through the Base-emitter junction of Q2.

My suggestion would be to take one step back and learn about diode logic.
https://en.wikipedia.org/wiki/Diode_logic
Then learn how to make an INVERTER from a transistor
Then add the two together to make NAND and NOR gates.

 

I would thoroughly recommend the section on CMOS in this publication.
https://worldradiohistory.com/UK/Electronics-Today-UK/ETI-Electronic-Circuit-Design-No-1.pdf
starting on page 4.
If you've mastered that, then the section entitled "CMOS to Mains" starting on page 77 is also really useful.
[Edit]
There's also an interesting section called "Digital electronics by experiment" in Volume 2
https://worldradiohistory.com/UK/Electronics-Today-UK/ETI-Electronic-Circuit-Design-No-2.pdf