How to use “find” command with several conditions

It is complaining because you have not quoted the *.txt so the shell is expanding the pattern instead of passing it to find. In other words, let's say you are in a directory that contains these files:

 foo.txt bar.txt baz.txt

When you say find . -name *txt -print the wildcard (*) is expanded by the shell (bash probably) so what is passed to ffindis actually:

find . -name foo.txt bar.txt baz.txt -print

That's too many arguments and find complains. To get what you want, you need to quote the pattern you a re searching for (you also don't need the -print for what you are doing):

 find . -name "*txt"

find . -regex "\./#.*#\|\./.*~"

Does this work for you?