Ah it's a daunting prospect, buying a house, especially for the first time. You need a good sense of the local housing market, the housing stock available and how demand and prices are faring in your preferred location. Otherwise you are all at sea and it's hard to get your bearings.
You are right to prioritise location with good transport, access and amenities, including schools, hospitals and council services. And a nice quiet street.
Type of house: you are right not to go for a renovation; it wouldn't suit you and is totally impractical for your situation. Be firm and clear - unwavering - about this with your relatives in order to move a step further along the decision process. If you have no clarity about what you want, neither will they.
You want a house of sound construction re roof, walls, drainage, doors, windows etc and in good condition in interior fittings and general decor, and of good size, which is not just the overall size but good individual room sizes and good workable layout of rooms; good light and orientation - where does it get the sun and light in the morning, afternoon and evening? - and some outside space for e.g. parking, bins, gardening, sunning yourself or escaping the heat in hot summers.
An end of terrace or a semi detached is preferable to a mid terrace, though we all have to buy what we can afford and I did once buy a mid terrace. Afterwards I thought I hadn't made a low enough offer and consequently overpaid for it. That's very common when people are not experienced buyers or negotiators, which is many if not most of us; there's a psychological pressure from the very fact of the asking price even though there is no compulsion or magic power attached to that figure. There's also the psychological pressure from the fear of losing the house you have decided to go for and set your heart on.
The best way to arm yourself is to be well informed about the local market and comparable houses and asking and sold prices, and apply that knowledge when considering what to offer. As a precaution against naive over offering, start lower than the figure you first think you should offer; be patient, hold your nerve and don't panic. It's a common assumption to start at 10% below asking price but you can't apply that to every house as asking prices can vary so widely, depending on the individual seller.
I wouldn't buy a house if I didn't like the look of the outside and couldn't change it, as it would be a permanent negative. If something annoys you on first viewing, I think the annoyance is going to be magnified if you live in it. Imagine seeing it every time you went in or out for years on end.
As far as your relatives go, and they want to sell their other houses and live near you, how about looking for two smallish rather than large houses in your preferred location, one for you and one for them, near to or even next to each other? A family in my neighbourhood bought two small attached semis, one for the elderly parents and one for their daughter. You are not just a passive recipient. Try to be decisive and lead them in the direction you would want.
Don't be apologetic about what you want or think you are being frivolous. Buying a house is a mixture of the irrational or emotional - liking, dreaming and envisioning, feeling and falling in love - and the rational: practical, sensible, and financial. When the right mixture of those elements comes together in harmony that chimes with you, it will result in happiness with your decision and a sense of satisfaction with your purchase.