I have listed several questions, thank you for all your insight.
1. Do i need to tell webroot to scan for malware or does it do by default?
2. Is it ok to run an additonal anti-malware program like free malwarebytes manuall?
3. If i get a virus on my iphone will it infect my pc or will webroot catch it? Iphone is not protected.
Best answer by RetiredTripleHelixView original
1. After install it will scan every day on it's own which takes about 2 minutes and is always keeping an eye on your system, here is the Online help file if you want to change your scanning schedule and other settings. Online Help File
2. Yes it's fine to use MBAM but if you do become infected please Submit a Support Ticket to let Webroot take care of it as it's free with your subscription if you use other tools it could cause complications to your system.
3. Yes WSA will protect your PC from infections that could come from your iPhone also if you have Webroot SecureAnywhere Complete you can protect any 5 devices including your iPhone also Back Up & Sync for iPhone