sounds like a good starter mate
i started with the 705 but have now got a GM 1000 and handed the 705 onto reefer he likes it as well nothing wring with them at all
just remember keep it low and slow and if it beeps then dig it until you know what each reading means
best way to practice is in your back yard and see what you find i spent days doing that could build a house with the nails and screws i found
also bury some coins a jewelry then run the 705 over them is another good way to do it