Can I get married on Tanabata? Is there anything you want to say ~

Sure, but it's still too early for you to get married in 2008. In 2008, the Qixi solar calendar falls on August 7th, just one month away from the lunar calendar. As for what to avoid, you can check heavenly stems and earthly branches that day and then check your date of birth. If you are not in a hurry, you can!