I have quite a few pots, and I have found that a drip irrigation system really helped me keep on top of watering. This system works well - once you’ve got the hang of it you can extend it with additional components https://www.amazon.co.uk/Hozelock-Easy-Micro-Watering-Containers/dp/B01AXKVWV2
Pots also need feeding, not just water. You can use various different things like liquid seaweed, tomato feed, chicken manure pellets, slow release fertiliser - but if you don’t feed regularly, most potted plants won’t flower well (there are exceptions but that’s the general rule).
Get the largest pots you can afford - they will have more impact and will retain moisture. Small pots especially terracotta will dry to a crisp really quickly. You can get cheap pots from places like Home Bargains, or ask your neighbours - I get a lot of free pots from people on my street. As a general rule of thumb aim for pots that are at least 30cm wide, unless you want an arid garden with succulents and drought tolerant plants.
If you do a list of flowers you like, we can advise if they are suitable for pots.
Make sure to get things in varied heights, not just bedding plants. Pots are a lot more impactful if they have something big in them. I like to grow cannas in pots, they get huge (2+ metre high) and have a real wow factor. I also like to scatter Californian poppy seeds in lots of pots around other flowers, they are very easy to grow and look gorgeously dishevelled.
Also think about adding foliage plants like ferns, coleus, ivy, mind your own business and creeping Jenny. They give texture and structure around flowers and prolong the season.