Need your best toilet training tips 🥲

Hey guys so we’ve (me 21, mum and dad) recently got a puppy. He’s almost 6 months and was a rescue from Cyrus so had a bit of hard start. We’ve had him one week (not long I know, I’m not expecting miracles but I’ve already cried 3 times this past week so I need help 🥲). He’s got virtually no training and we’ve been focusing on positive reinforcement for going toilet outside. However, he comes back inside and within 10 minutes he pees on the floor again. I’ll take him out and he’ll do nothing and come in a pee on the floor again. He’s not started asking to go outside yet so how do I catch it and stop him peeing inside? He’s a chihuahua cross and moves so fast he’s peed before we even know it, he needs constant watching and I’m honestly so tired. I’m his main carer, dad isn’t very involved (in anything tbh lmao) and mum is sick of it already. Please any tips you have I rly need them and please be kind. We’ve had many dogs and we’ve never had this much trouble before. TIA 🩷