I want to paint my house, brushing is hard work, should I look at a conventional, airless or HVLP sprayer to make it easier?
Please remember I have never used any of these.
If you want to make the task of painting your house easier, you may want to consider using a sprayer. Out of the three options you mentioned - conventional, airless, and HVLP (high volume, low pressure) sprayers - HVLP sprayers may be the best choice for you, especially if you're a beginner. Here's why:

HVLP sprayers are easy to use and control, making them a great option for inexperienced users. They produce a soft, fine mist that's easy to apply, even to hard-to-reach areas, and the low pressure means that you can avoid overspray and drips.

HVLP sprayers are versatile and can be used to paint a variety of materials, including wood, metal, and drywall.

HVLP sprayers are less messy than other types of sprayers, and they're less likely to create a lot of overspray and waste.

However, it's important to keep in mind that HVLP sprayers are slower than airless or conventional sprayers, so if you have a large area to paint, it may take longer to complete the job.
What would be the cheapest option, while still being effective?
If you are looking for the most cost-effective option, you may want to consider a conventional sprayer. Conventional sprayers are typically the least expensive option, and they can still be effective in painting your house. The downside of using a conventional sprayer is that they are not as efficient as airless or HVLP sprayers, and you may need to apply more coats of paint to get the desired results. Additionally, they can be more difficult to use and control, and they may produce more overspray than other types of sprayers.