Check Bill Frederick Park at Turkey Lake. Long name but is very close to Universal. FHU sites are $18 nt. Park has pool, walking trails, large playground.
Downside is you must call for a site they are city owned and are not online.
When will you be there? We will be camping there April 18-20 with FL Pop up campers (FPUC) for the weekend.
Turkey Lake Park
3401 Hiawassee Road, Orlando 32835
(407) 299-5581, (407) 299-5594
Admission: $4 per car ($2 if it's just the driver)
Hours: Daily 8:00 a.m. to 5:00 p.m. November to March; 8:00 a.m. to 7:00 p.m. April to October
Location: From I-4 Exit 75 take Kirkman north, turn left onto Conroy then right onto Hiawassee to park entrance, about 4 miles total