The reason you can’t vote is because you are still a “new member”.
Once you become a “member”, you will be able to vote.
In order to advance to Trust Level 1 (TL1) - Member, you must:
Enter 5 topics
Read 5 posts
Spend at least 15 minutes reading posts
At TL1, users will be able to:
Voting: 10 active votes allotted. If the topic is closed or archived, the votes are released to the users and can be applied to other topics but the vote count on the topic remains.