I have bought an NTSC (Region 1 USA) VCR by mistake. I am in Europe,
Region 2, with Pal VHS system. Will I be able use this VCR in Europe
by using just region 1 video cassettes? If it won't, is there any
company that change NTSC to Region 2 system? The VCR is still in the
US waiting to be shipped.

You can watch NTSC tapes played on the NTSC VCR if you have an NTSC TV.

You can find a device that will change the NTSC signal generated by
the NTSC VCR to PAL (or SECAM, if you are in France). It will cost you
more than it is worth, however.

It does not matter if you use the RCA inputs or the antenna input. In
the unlikely event the NTSC VCR has a SCART plug (not going to happen,
my friend), you can view the signal on a SCART-equipped TV. I think.

My part of Europe (the UK) is now awash with VCRs that handle both PAL
(Europe) and NTSC (North America).

The Region stuff really applies to DVDs: Region 1 North America;
Region 2 Europe; etc.

My part of Europe is also awash with DVD players that are
'multi-region'. What's more they are really cheap.

Which part of Europe are you in?