Owners of military vehicles will hold a display at the event which includes music and children's crafts.
A memorial in honour of veterans lost to suicide will travel from North Yorkshire to Staffordshire.
More than 6,000 British armed forces personnel were injured, and 179 killed, in the 2003 Iraq war.
The visitor attraction is hosting a weekend of celebrations to mark 25 years since it opened.
The site is to be known as the Royal British Legion National Remembrance Gardens from September.
The estate said earlier this month it will become the Royal British Legion National Remembrance Gardens.
Organisers confirm the design for the memorial to pay tribute to journalists killed in conflict.
Directors say the rebrand of the site, home to more than 420 memorials, will help future investment.
A community with deep bonds has developed around an annual ride to remember armed forces service personnel.
