Need advise. Want to build a Spanish Civil War I16 russian bomber. Which kit to buy?

Usually I pour some of the R-3 brake fluid into a glass bowl and holding a model with one wing I dip the second one into the fluid. It has to stay there for a while then using a thick brush I start removing a paint still keeping the model wing dipped in the fluid. When all is removed I use a soft , soaked with the R-3 fluid, rag for cleaning "washed" area. Please remember that after cleaning a model has to be washed up with a warm water and soap. If I use the WAMOD fluid I remove a colour with soaked soft rag.
Also I suggest making a test with a piece of the model sprue frame dipped in the R-3 fluid. Just in case if the R-3 could damaged the polistyrene.

Where could I buy Wamod fluid? Can I just use the rag to remove the paint?

If you use the Wamod one yes you can remove a paint with soaked rag. The Wamod remover is offered by almost all LHSs here in Poland. In the USA you has to chack on-line shops. It's possible one of them may have it in its offer.
Therefore I suggested the R-3 brake fluid because it is usually offered in all countries.

I'm thinking any kind of brake fluid would do; Castrol, STP etc.. I've used Nail polish remover in the past with some success, but as Wurger says, test it first. Why don't you post a photo of your model first before trying to remove the paint.

Geo

Or try these Modelstrip Paint stripper for removing paint # MODSTR01
MODEL PAINT REMOVER :: Mtsenbcker's Lift Off



Geo

Yep... this can be used as well.

And also the one.... AK INTERACTIVE 119 - Perfect Cleaner - Universal Cleaner for Acrylic Paints




links..

http://www.ak-interactive-usa.com/119.html

and a link for getting contact with the AKI in the USA..

http://www.ak-interactive-usa.com/contact.html

Seriously, though, This is your first model. It looks as if you rushed through it. If you look at some of the builds posted here you will get an idea of how things are done. And you are welcome to ask as many questions as you want.
A wise man once said, "Modeling is not a race."

So what is the way to make these? Do you paint first, or assemble and then paint. I am talking about the fuselage, not the details.

Here is the thing, This will not be done in an afternoon. several weeks is more the norm.
O.K., in a nut shell, Remove the kit from the packaging, wash it in a mild dishwashing soap. This removes oils that are present in the molding process. You can pat dry with a soft cloth, or sun dry. Study the instructions, usually as these things are drying. Clip the parts from the sprues using a set of nail clippers, or a more advanced "sprue nipper" (Sold at the local hobby store, or available on-line). Follow the instructions, (at least at this point, later you will know when to deviate,) and test fit all parts. Let me say this again, test fit all parts. Place them together without glue to see how they fit. O.K., let me say that again, Test fit!!!!
Sometimes the "pins" aren't "on". If they aren't,... well cut them off, and fit the bits together as they should be.
Now, That you have fit the parts, and they look good, It is time to glue. Use a liquid glue, not that tube stuff. Put some into a cup and use a toothpick to apply. don't be afraid to apply too much to the seams, you want a good "bead' along the edges. If everything is lined up right, this bead is just what you want. Patience is the key. You can use various clips and rubber bands to hold the parts together, and in place. Wait about 24 hours to be sure that the glue has dried.
Carefully shave off the "bead' that is from the glue joint with a sharp #11 X-acto, or something similar, then inspect for imperfections, (and there will be some.), Fill any of those with a putty, and then sand. And sand again. Then sand some more, with progressivily finer grades of paper. (Most of us use 1200 grit to finish.) You can use a brush to paint, this is not a problem. Remember to use a fine cloth to wipe the model down, or wash it again before trying to paint. A primer coat is recommended. This helps to identify any imperfections on the surface before the initial coat goes on. If you see any, use a bit of putty and sand, and sand, and sand again. Then paint with the primer and if satisfied try the color.
Once you are satisfied with the paint color, an application of Future acrylic is recommended. This provides a smooth surface for the decals to "fix", Then a coat of "matte" and you are done.
Unless you want to do some "weathering". That is a whole 'nother thing.
That about covers it, I think.
If anyone comes up with a couple of other points, please feel free to add.

I definitely rush through it. I will try paint remover and see if I can save it.

Well done Paul.