You will have to supply the path to the cert and specify its password in the local.properties file of the Workstation using the below properties. Please note that these properties define the keystore of the Workstation.
To specify the truststore, you can
(a) Either import the trusted certs in to cacerts.jks, default truststore of DevTest, located under "LISA_HOME\jre\lib\security" folder.
(b) Or create a truststore and supply it to DevTest using the properties below in local.properties file.
Please note that creating JKS files and importing the certs in to it is not a product feature but JAVA feature which can be done in various ways like using keytool commands or using openly available tool called "Portecle".
2) I have a SSL certificate and a password and I am able to work in SOAPUI using these information. Do I need alias key and password and if yes, how can I do get it or is there a way to do it without using those.
Certificate can also be supplied by importing it into a JKS file and giving the JKS file as the keystore using properties mentioned above. While creating the JKS, it is required for you to supply alias and key password for JVM to identify the cert it needs to use from that JKS.
If you have only one Cert for all the test cases, then you may not need to create a JKS.