Helping a first time home buyer

Hello everybody, it's my first post here after months of reading and lingering on this sub.

I wanted to get some advice on buying my first home, and I think I'm in a more unique circumstance which I'm hoping to get help on.

Background: 27 years old 4 years of work experience, medium job security, current salary 85k gross, 5.2k in hand/month. Can absorb ~3k in mortgage + maintenance + extras per month. Net worth: 130k (TFSA, FHSA, rest in non registered). No debt, no car, no partner (yet). Mortgage: spoke to a specialist at my bank at RBC and was directionally offered ~400k at approx 4.75% 5 year variable. Not pre approval, but it's what I'm anchoring on. Downpayment: can cough up ~300k between my accounts and a gift from my parents, liquid and ready to offer in the next 3 months.

Situation: I've been living in the same unit in core downtown (City place) for the last three years and have built a good relationship with my landlord. Recently, given market trends and conditions, I've been interested in buying a place for my primary residence (not an investment). Opening the topic with my landlord, he is willing to sell me the unit. The unit is 650-700sqf, 1+1, very good layout and quite livable for a couple or even a single child household. Given that we both know each other and I've lived here for three years, there is no point getting a realtor involved, and instead we can save the 5% fees. Preliminary search on Condos.ca suggests listing's are struggling with months on market only to be terminated and reposted at lower rates. Approx rates are 900-950/sqf. Maintenance fees is around $0.85/sqf.

Questions: How should I approach negotiating with my landlord on this purchase? Given no realtor, should I discount 5% from the listings I see?

Since there is no realtor involved, how should I think about mortgage brokers or lawyers or other people involved? Since I've lived here a long time, an inspection is not necessary.

How does one go about shopping for a mortgage? I've checked my bank, should I walk into other bank branches like cibc or td and just pop the question at the reception?

I think it's a buyers market right now, and prices may or may not fall further, but I'd rather pull the trigger in the next 6 months (not rushed) and build equity than try and time the market.

Sorry for the long post, but I know this sub likes to have a lot of info/data upfront.

Thank you so much in advance!

TLDR: New first home buyer, looking to buy the unit I'm renting from my landlord. Since we don't need a realtor, wondering how I should think about engaging other people in the chain like lawyers and mortgage brokers. Also unsure how mortgage shopping works, and how to ask banks for rates and other features. Lastly, am I missing something obvious as a first time home buyer?