Using multiple templates on one site?

No, Blot doesn't support using multiple templates on one site – however, you could manually merge features from multiple templates into a single new template but this would involve editing code. Another option is to create two sites and use them on seperate subdomains, rather than URL paths.

Does that help? Please let me know if you have any questions about this or anything else.

I moved your second question into its own thread.

For the combination of multiple template, does it means that I have to use if...then for controlling? If yes, do you mind to check if I can set the folder path in conditions?

It's not possible to use if...then based on folder path but you could use tags to style different types of posts in different ways. But I'd suggest digging into the source code for two of the templates you'd like to merge first. Please let me know if you have any questions