"I just purchased a product with THCA:141mg, CBD:0,THC 21mg. Will this produce anxiety as there is no CBD?"
Please keep in mind that THCA is the unactivated version of the cannabinoid THC. Although THCA is considered non-psychoactive, when THCA is aged or heated it changes into THC, the psychoactive compound in cannabis.
If the product you purchased has no CBD present, I am afraid there is a possibility you may experience a little anxiety. With that said, remember that cannabis effects everyone differently. For some, THCA can cause energizing effects, but can also cause others sedative effects. The same applies in relation to anxiety. THCA may alleviate anxiousness, however the THC present may increase it.
Be sure to keep a CBD product handy in case you experience an anxiety attack. If you do find yourself suffering from a cannabis-induced anxiety attack, try to listen to music that makes you happy or drink a hot cup of tea. Any soothing activity will help you relax. You can find more suggestions about stopping a cannabis-caused anxiety attack here: https://www.hellomd.com/health-wellness/58ac759d05b7950007646b95/how-to-stop-a-marijuana-induced-anxiety-attack
You can also read more about THCA and all it's benefits.
I hope this information helps! :-)