It's lovely that you and your girlfriend have your parents' permission and that you want to approach this situation thoughtfully. However, it's important to remember that you are both still very young, and kissing is something that typically involves more maturity and understanding of relationships.
At the age of 10, it's essential to focus on building strong friendships and learning about respect, communication, and healthy boundaries. Romantic relationships at such a young age can be complex and may not have the same depth and understanding as relationships that develop later in life.
Instead of focusing on kissing, you can express your feelings for your girlfriend through other means. Spend time together, talk openly and honestly, and enjoy each other's company as friends. As you both grow older and have more experience in understanding relationships, you'll have a better context for what feels right and when you may be ready for different expressions of affection.
Remember that there is no rush, and it's essential to enjoy your childhood and adolescence without feeling pressured to engage in romantic relationships beyond what feels comfortable for you.
If you have any questions or concerns, you can always talk to a trusted adult, like your parents or a school counselor, who can offer guidance and support. They will be able to provide you with age-appropriate advice based on their knowledge of your unique situation.