It’s hard when it’s all so new. First off try and find a suitable donor on the site, try searching for men near you and don’t just wait for any to come to you. It helps if you take the lead! You have to main methods of conceiving: Artificial Insemination (pot and syringe) or natural Insemination (intercourse). Each has advantages and disadvantages and the choice is a personal one. Obviously natures way has more chance of success, but that doesn’t mean AI can’t work for you if you are young enough.
STI checks are a must for him and also for you if using NI. Worth mentioning that most NHS hospitals will do a free STI check, some larger ones by just walking in. They will text you your results. Beware of men offering supposed certificates from private clinics. Why would you pay ¬£200-¬£300 for this? There are plenty of fake certificates on the web, I wonder if that’s the reason?!!