You can apply online for an “e-visa”. The Uganda Electronic Visa/Permit Application System can be accessed here. You should give yourself sufficient time to apply for a visa and make sure when applying that the start date and validity covers the period of the meeting/your stay in Uganda.
Your passport should be valid for a minimum period of 6 months from the date of entry into Uganda.
Yellow Fever Vaccination
A certificate of yellow vaccinatuon is required from travels arriving to Uganda from countries with risk of yellow fever transmission. The list of these countries can be looked at here.