Been a team lead in title at my company (small software company, out of the start up phase, but was a startup when I joined)) for over a decade. Only figured out how to be a leader in reality over the last 5ish years.

Do you want the title of team lead, or to actually be a leader on your team? Those are often two different things.

Getting the title depends a lot on the politics of your employer. A good place will promote based on merit, others won't.

Being an actual leader is actually a lot more straightforward: serve the team. Be the driving force behind improving their work lives. That means communicating with them regularly both about what they are finding difficult (and then being a driver in finding a solution) and celebrating them when things go well. It means being a champion for the good ideas others have. It also means asking for help from the team when it's needed; stay humble.

Through this constant communication a couple of things should start to happen:

• you'll be able to piece things (solutions, product improvements, bug fixes, etc) more quickly, because your domain and contextual knowledge will be greater than those not serving the team.
• other team members will start coming to you for things, people will naturally gravitate toward those that have proven to be helpful
• the team will start outputting higher quality product
• life for the team will get more enjoyable

Do all that and people will start naturally looking to you.