With regard to your lodging needs, there are three hotels in the immediate vicinity of the Galveston Island Convention Center and each are within walking distance from the Convention Center:
Hilton Galveston Island Resort (www.galvestonhilton.com), which is the closest hotel (approximately 50 steps from the Convention Center). The Galveston Hilton has reserved a block of rooms at the special price of $129 per night when booked by February 6th, 2019. If you have a browser issue please copy and paste this line in to a new window. https://secure3.hilton.com/en_US/hi/reservation/book.htm?execution=e1s1
The San Luis Resort (www.sanluisresort.com) is located 2 blocks from the Convention Center and is about a 5 minute walk.
Holiday Inn Resort Galveston (www.galvestonholidayinn.com). This property is located about 2.5 blocks from the Convention Center and will be about a 5-10 minute walk.
Other Galveston hotels can be found Galveston Hotels.