Yes, you are able to deduct expenses associated with talks and other paid or unpaid engagements, especially if they promote your business or expertise.
Travel expenses are best deducted in the travel lines of your Profit and Loss statement. Rental Cars, Hotel/Motel, Airfare, Uber/Lyft, Taxi, Ground Transportation are all costs that can be associated withe travel exepnses.
Meals are only deductible at 50% and Entertainment is non-deductible, so you want to make sure you are careful in regard to these costs when traveling.
Other incidentals are not deductible if personal in nature. Business use of wifi fees on the plane, a common cost, however, can be included, as long as you are not co-mingling with movie watching.
Something to remember, if you are adding costs on paid engagements, you may want to negotiate the costs of meals into the contract. In so doing, you are able to include the full cost into the invoice and have the meals covered. However, remember, you are still only able tot deduct 50% of those meals on the tax return.
