The company I work for has got an Adobe Creative Cloud Teams account. I see that it comes with a 30 day free trial of stock. But it seems like I have to switch to the individual account for it. So if I'm downloading/buying a pic from Adobe Stock for work purpose, do I need to purchase the teams license or can I use the 'free trial' to download it and then use it.
Using the Adobe ID you are using here on the forums I see that your company does not have any Adobe Stock subscription. If you would like your team to have such a subscription you can make a request of your administrator by signing into Adobe Stock, selecting your company name from the profile menu and navigating to https://stock.adobe.com/uk/teams and clicking the Buy Now button for any of the subscriptions you'd like to request. You can do the same for credit packs.
If your team wants to try before buying your team administrator can sign into Adobe Stock and select the company name from the profile menu and the administrator will receive an offer for 10 free Stock assets for the team.