Is a Trademark Clearinghouse registration similar to a domain registration?
No, a Trademark Clearinghouse (TMCH) registration does not give you any domain registrations. However, it is a prerequisite if you want to register yourtrademark.tld in the Sunrise periods of a new gTLD.
If you want to register yourtrademark.tld, you will have to order the domain registration as you order any other domain registration in Openprovider.
Also the costs of a TMCH registration are independent of a domain registration: you pay the TMCH fee, and for each domain registration you pay the normal domain fee. In most cases, registration in the Sunrise period will be charged a different price than registration during other stages.