Hi Mark.The processes are the same no matter what the batch size.
What changes is your need for precision, if your strike water was a degree or two off in a 50L batch it would have 10 times the effect at 5L. I do a lot of 10L batches, and 200L batches so get to experience this pretty regularly.
Make sure you have a good measuring jug (I use a 5L jug) and a good thermometer (I use a glass lab thermometer and not a crap one). The easiest way to start would be BIAB, get a pot at least twice the size of your batch (or close, the famous 19L pot is good).
Plan, know your strike water temperature and volume, make sure you mash in just a touch under target then top up with a bit of boiling water to hit your targets. Same applies if you want to add hot water (boiling) to get to a mash out, do the calculation, add a bit less then adjust when its stabilised. Overshooting temperatures causes a lot more damage than does undershooting for a short time.
Do simple beers for a start, something basic like a Coopers Pale Ale clone, if you make hop monsters from day one you wont be able to taste what you are getting from your grain bitt, there will be issues and you will need to learn how to get the most out of you malt.
Personally I would be doing some SMASH (single malt and single hop) beers. Budvar, one of the finest pilsners in the world is made from one malt, one hop and one hop addition, I have always thought when you can brew that well it might be time to think about a second malt/hop/addition...
Find a club or like where you can get your beers tasted critically, look for mistakes and learn how to fix them.
I would do the same brew a couple (3) times in a row, gets you really familiar with your equipment and processes.
Keep good records! Knowing what you have done and how the beer turns out helps you make the beers you want.
Remember that making beer is easy, making really good beer consistently and repeatedly is bloody hard, it requires knowledge and control of your processes, fortunately its a bundle of fun - welcome aboard.