CSR is it SHA1 or SHA2

You can use openssl

openssl req -text -noout -verify -in my.csr

The signature algorithm should be displayed towards the bottom. SHA1 is a 160 Bit hash, SHA2 is a family of hashes, most commonly used is 256

In my example, it's SHA2 as a 256 hash is used.

 -- output omited -- 

         Exponent: 65537 (0x10001)
    Attributes:
        a0:00
Signature Algorithm: sha256WithRSAEncryption
     36:7a:46:3e:49:a5:ec:a6:f8:a7:ff:fc:e4:58:d5:06:0d:fc:
     4a:25:a3:c8:f0:65:87:15:f9:30:8d:c7:fd:05:e9:1f:bb:77:

 -- output omited --