What are the best practices for small businesses and startups using AI and Emerging Technologies? How do these practices differ from those at large  corporations and enterprises?

Focus on problems and develop solutions to those problems. Never start with a solution and look for problems to solve with it.

Your first phase would look at saving a small businesses most valuable resource, the time of their employees. Look at what repetitive tasks are eating your employees time and note them all as a list. Go through the list and look for readily available solutions to those problems. If there isn't one, move on to the next problem. The goal here is to find existing solutions that you can immediately adopt to automate reputative tasks and free up the time of your small number of employees. 

The next phase will be about augmenting your business though data and insights. This could be data and information storage about clients/customers, user demographics etc that you would analyze to increase revenue

These differ from large organizations in that in enterprise it is very difficult to simply adopt new systems to solve problems. Entire change processes, procurement and procedures must be followed. Small businesses also typically have more employees with a specific focused skill set, something that makes automation effective and wide reaching. Whereas in enterprise you have different departments, offerings, business units all with different operations, making automation specific to teams or departments (a smaller overall percentage of the business will gain value from the automation when compared to a small business)

Network Automation will focus on more strategic solutions as a pipeline for infrastructure delivery instead of point solutions. 
Multi-Cloud will be a large part of any Cloud adoption to normalize Public Cloud connectivity with other resource locations
NaaS will become the new Telco Service and start to eat away at traditional MPLS and WAN infrastructure 
SD-WAN will become a 'feature' of SASE products and vendors who do not have a SASE solution will start to get eaten or fall apart
The year of the SMartNIC in Enterprise (I hope) because of increased virtualized Network and Security workloads that need more bandwidth and higher throughput